WorldWideScience

Sample records for pulsed laser deposition

  1. Pulsed laser deposition: Prospects for commercial deposition of epitaxial films

    Energy Technology Data Exchange (ETDEWEB)

    Muenchausen, R.E.

    1999-03-01

    Pulsed laser deposition (PLD) is a physical vapor deposition (PVD) technique for the deposition of thin films. The vapor source is induced by the flash evaporation that occurs when a laser pulse of sufficient intensity (about 100 MW/cm{sup 2}) is absorbed by a target. In this paper the author briefly defines pulsed laser deposition, current applications, research directed at gaining a better understanding of the pulsed laser deposition process, and suggests some future directions to enable commercial applications.

  2. Pulsed laser deposition of rare earth compounds

    CERN Document Server

    Stone, L A

    2001-01-01

    Magnetostrictive thin films have been deposited using various techniques such as sputtering and evaporation but the use of laser deposition has been limited. This research presents the results from pulsed laser deposition (PLD) of TbFe sub 2 , DyFe sub 2 and Terfenol-D thin films using an infra red Transversely Excited Atmospheric (TEA) CO sub 2 laser at lambda approx 10.6 mu m and an ultra violet Argon-Fluoride (ArF) excimer laser at lambda approx 193 nm. Results have showed that the TEA CO sub 2 laser under the range of conditions studied is not suitable for the production of magnetostrictive films. The problems experienced are a mixture of mostly fracture debris at low fluences (F approx 20 Jcm sup - sup 2) and melt droplets at high fluences (F approx 60 Jcm sup - sup 2). In all cases the destruction of the target is a major problem, with the Terfenol-D targets being the worst affected. Thin films produced were all iron rich. The use of an excimer laser has proved more successful in providing stoichiometri...

  3. Pulsed laser deposition of pepsin thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kecskemeti, G. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary)]. E-mail: kega@physx.u-szeged.hu; Kresz, N. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Smausz, T. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Hopp, B. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Nogradi, A. [Department of Ophthalmology, University of Szeged, H-6720, Szeged, Koranyi fasor 10-11 (Hungary)

    2005-07-15

    Pulsed laser deposition (PLD) of organic and biological thin films has been extensively studied due to its importance in medical applications among others. Our investigations and results on PLD of a digestion catalyzing enzyme, pepsin, are presented. Targets pressed from pepsin powder were ablated with pulses of an ArF excimer laser ({lambda} = 193 nm, FWHM = 30 ns), the applied fluence was varied between 0.24 and 5.1 J/cm{sup 2}. The pressure in the PLD chamber was 2.7 x 10{sup -3} Pa. The thin layers were deposited onto glass and KBr substrates. Our IR spectroscopic measurements proved that the chemical composition of deposited thin films is similar to that of the target material deposited at 0.5 and 1.3 J/cm{sup 2}. The protein digesting capacity of the transferred pepsin was tested by adapting a modified 'protein cube' method. Dissolution of the ovalbumin sections proved that the deposited layers consisted of catalytically active pepsin.

  4. Pulsed laser deposition of nanostructured Ag films

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, Tony [School of Physics, Trinity College, Dublin 2 (Ireland); Doggett, Brendan [School of Physics, Trinity College, Dublin 2 (Ireland); Lunney, James G. [School of Physics, Trinity College, Dublin 2 (Ireland)]. E-mail: jlunney@tcd.ie

    2006-04-30

    Ultra-thin (0.5-5 nm) films of Ag have been prepared by pulsed laser deposition in vacuum using a 26 ns KrF excimer laser at 1 J cm{sup -2}. The deposition was controlled using a Langmuir ion probe and a quartz crystal thickness monitor. Transmission electron microscopy showed that the films are not continuous, but are structured on nanometer size scales. Optical absorption spectra showed the expected surface plasmon resonance feature, which shifted to longer wavelength and increased in strength as the equivalent film thickness was increased. It is shown that Maxwell Garnett effective medium theory can be used to calculate the main features of optical absorption spectra.

  5. A new pulsed laser deposition technique: scanning multi-component pulsed laser deposition method.

    Science.gov (United States)

    Fischer, D; de la Fuente, G F; Jansen, M

    2012-04-01

    The scanning multi-component pulsed laser deposition (PLD) method realizes uniform depositions of desired coatings by a modified pulsed laser deposition process, preferably with a femto-second laser-system. Multi-component coatings (single or multilayered) are thus deposited onto substrates via laser induced ablation of segmented targets. This is achieved via horizontal line-scanning of a focused laser beam over a uniformly moving target's surface. This process allows to deposit the desired composition of the coating simultaneously, starting from the different segments of the target and adjusting the scan line as a function of target geometry. The sequence and thickness of multilayers can easily be adjusted by target architecture and motion, enabling inter/intra layer concentration gradients and thus functional gradient coatings. This new, simple PLD method enables the achievement of uniform, large-area coatings. Case studies were performed with segmented targets containing aluminum, titanium, and niobium. Under the laser irradiation conditions applied, all three metals were uniformly ablated. The elemental composition within the rough coatings obtained was fixed by the scanned area to Ti-Al-Nb = 1:1:1. Crystalline aluminum, titanium, and niobium were found to coexist side by side at room temperature within the substrate, without alloy formation up to 600 °C.

  6. Pulsed laser deposition of tantalum pentoxide film

    Science.gov (United States)

    Zhang, J.-Y.; Boyd, I. W.

    We report thin tantalum pentoxide (Ta2O5) films grown on quartz and silicon substrates by the pulsed laser deposition (PLD) technique employing a Nd:YAG laser (wavelength λ=532 nm) in various O2 gas environments. The effect of oxygen pressure, substrate temperature, and annealing under UV irradiation using a 172-nm excimer lamp on the properties of the grown films has been studied. The optical properties determined by UV spectrophotometry were also found to be a sensitive function of oxygen pressure in the chamber. At an O2 pressure of 0.2 mbar and deposition temperatures between 400 and 500 °C, the refractive index of the films was around 2.18 which is very close to the bulk Ta2O5 value of 2.2, and an optical transmittance around 90% in the visible region of the spectrum was obtained. X-ray diffraction measurements showed that the as-deposited films were amorphous at temperatures below 500 °C and possessed an orthorhombic (β-Ta2O5) crystal structure at temperatures above 600 °C. The most significant result of the present study was that oxygen pressure could be used to control the composition and modulate optical band gap of the films. It was also found that UV annealing can significantly improve the optical and electrical properties of the films deposited at low oxygen pressures (<0.1 mbar).

  7. Pulsed laser deposition: metal versus oxide ablation

    NARCIS (Netherlands)

    Doeswijk, L.M.; Rijnders, G.; Blank, D.H.A.

    2004-01-01

    We present experimental results of pulsed laser interaction with metal (Ni, Fe, Nb) and oxide (TiO2, SrTiO3, BaTiO3) targets. The influence of the laser fluence and the number of laser pulses on the resulting target morphology are discussed. Although different responses for metal and oxide targets t

  8. 25 years of pulsed laser deposition

    Science.gov (United States)

    Lorenz, Michael; Ramachandra Rao, M. S.

    2014-01-01

    It is our pleasure to introduce this special issue appearing on the occasion of the 25th anniversary of pulsed laser deposition (PLD), which is today one of the most versatile growth techniques for oxide thin films and nanostructures. Ever since its invention, PLD has revolutionized the research on advanced functional oxides due to its ability to yield high-quality thin films, multilayers and heterostructures of a variety of multi-element material systems with rather simple technical means. We appreciate that the use of lasers to deposit films via ablation (now termed PLD) has been known since the 1960s after the invention of the first ruby laser. However, in the first two decades, PLD was something of a 'sleeping beauty' with only a few publications per year, as shown below. This state of hibernation ended abruptly with the advent of high T c superconductor research when scientists needed to grow high-quality thin films of multi-component high T c oxide systems. When most of the conventional growth techniques failed, the invention of PLD by T (Venky) Venkatesan clearly demonstrated that the newly discovered high-T c superconductor, YBa2Cu3O7-δ , could be stoichiometrically deposited as a high-quality nm-thin film with PLD [1]. As a remarkable highlight of this special issue, Venkatesan gives us his very personal reminiscence on these particularly innovative years of PLD beginning in 1986 [2]. After Venky's first paper [1], the importance of this invention was realized worldwide and the number of publications on PLD increased exponentially, as shown in figure 1. Figure 1. Figure 1. Published items per year with title or topic PLD. Data from Thomson Reuters Web of Knowledge in September 2013. After publication of Venky's famous paper in 1987 [1], the story of PLD's success began with a sudden jump in the number of publications, about 25 years ago. A first PLD textbook covering its basic understanding was soon published, in 1994, by Chrisey and Hubler [3]. Within a

  9. CTS and CZTS for solar cells made by pulsed laser deposition and pulsed electron deposition

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt

    , which make them promising alternatives to the commercially successful solar cell material copper indium gallium diselenide (CIGS). Complementing our group's work on pulsed laser deposition of CZTS, we collaborated with IMEM-CNR in Parma, Italy, to deposit CZTS by pulsed electron deposition for the first...... time. We compared the results of CZTS deposition by PLD at DTU in Denmark to CZTS made by PED at IMEM-CNR, where CIGS solar cells have successfully been fabricated at very low processing temperatures. The main results of this work were as follows: Monoclinic-phase CTS films were made by pulsed laser...

  10. Imposed layer by layer growth by pulsed laser interval deposition

    NARCIS (Netherlands)

    Koster, Gertjan; Rijnders, Guus J.H.M.; Blank, Dave H.A.; Rogalla, Horst

    1999-01-01

    Pulsed laser deposition has become an important technique to fabricate novel materials. Although there is the general impression that, due to the pulsed deposition, the growth mechanism differs partially from continuous physical and chemical deposition techniques, it has hardly been used. Here, we w

  11. Pulsed laser deposition of ferroelectric thin films

    Science.gov (United States)

    Sengupta, Somnath; McKnight, Steven H.; Sengupta, Louise C.

    1997-05-01

    It has been shown that in bulk ceramic form, the barium to strontium ratio in barium strontium titanium oxide (Ba1- xSrxTiO3, BSTO) affects the voltage tunability and electronic dissipation factor in an inverse fashion; increasing the strontium content reduces the dissipation factor at the expense of lower voltage tunability. However, the oxide composites of BSTO developed at the Army Research Laboratory still maintain low electronic loss factors for all compositions examined. The intent of this study is to determine whether such effects can be observed in the thin film form of the oxide composites. The pulsed laser deposition (PLD) method has been used to deposit the thin films. The different compositions of the compound (with 1 wt% of the oxide additive) chosen were: Ba0.3Sr0.7TiO3, Ba0.4Sr0.6TiO3, Ba0.5Sr0.5TiO3, Ba0.6Sr0.4TiO3, and Ba0.7Sr0.3TiO3. The electronic properties investigated in this study were the dielectric constant and the voltage tunability. The morphology of the thin films were examined using the atomic force microscopy. Fourier transform Raman spectroscopy was also utilized for optical characterization of the thin films. The electronic and optical properties of the thin films and the bulk ceramics were compared. The results of these investigations are discussed.

  12. Resonant infrared pulsed laser deposition of thin biodegradable polymer films

    DEFF Research Database (Denmark)

    Bubb, D.M.; Toftmann, B.; Haglund Jr., R.F.

    2002-01-01

    Thin films of the biodegradable polymer poly(DL-lactide-co-glycolide) (PLGA) were deposited using resonant infrared pulsed laser deposition (RIR-PLD). The output of a free-electron laser was focused onto a solid target of the polymer, and the films were deposited using 2.90 (resonant with O-H str...

  13. Pulsed laser ablation and deposition of niobium carbide

    Science.gov (United States)

    Sansone, M.; De Bonis, A.; Santagata, A.; Rau, J. V.; Galasso, A.; Teghil, R.

    2016-06-01

    NbC crystalline films have been deposited in vacuum by ultra-short pulsed laser deposition technique. The films have been characterized by transmission and scanning electron microscopies and by X-ray diffraction. To clarify the ablation-deposition mechanism, the plasma produced by the ablation process has been characterized by optical emission spectroscopy and fast imaging. A comparison of the results with those obtained by ns pulsed deposition of the same target has been carried out.

  14. Bismuth thin films obtained by pulsed laser deposition

    Science.gov (United States)

    Flores, Teresa; Arronte, Miguel; Rodriguez, Eugenio; Ponce, Luis; Alonso, J. C.; Garcia, C.; Fernandez, M.; Haro, E.

    1999-07-01

    In the present work Bi thin films were obtained by Pulsed Laser Deposition, using Nd:YAG lasers. The films were characterized by optical microscopy. Raman spectroscopy and X-rays diffraction. It was accomplished the real time spectral emission characterization of the plasma generated during the laser evaporation process. Highly oriented thin films were obtained.

  15. Stoichiometric magnetite grown by infrared nanosecond pulsed laser deposition

    OpenAIRE

    Sanz, Mikel; Oujja, M.; Rebollar, Esther; Marco, J.F.; Figuera, Juan de la; Monti, Matteo; Bollero, A.; Camarero, J.; Pedrosa, Francisco J.; García-Hernández, M; Castillejo, Marta

    2013-01-01

    Pulsed laser deposition (PLD) is a versatile technique for the fabrication of nanostructures due to the possibilities it offers to control size and shape of nanostructured deposits by varying the laser parameters. Magnetite nanostructures are currently promising materials to be used in computing, electronic devices and spintronic applications. For all these uses the fabrication of uniform nanostructured pure magnetite thin films is highly advantageous. In PLD of magnetite, the laser irradiati...

  16. Pulsed laser ablation and deposition of niobium carbide

    Energy Technology Data Exchange (ETDEWEB)

    Sansone, M.; De Bonis, A. [Dipartimento di Scienze, Università della Basilicata, Viale dell’Ateneo Lucano 10, 85100 Potenza (Italy); Santagata, A. [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, UOS Tito Scalo, C.da Santa Loja, 85010 Tito, PZ (Italy); Rau, J.V. [Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100, 00133 Rome (Italy); Galasso, A. [Dipartimento di Scienze, Università della Basilicata, Viale dell’Ateneo Lucano 10, 85100 Potenza (Italy); Teghil, R., E-mail: roberto.teghil@unibas.it [Dipartimento di Scienze, Università della Basilicata, Viale dell’Ateneo Lucano 10, 85100 Potenza (Italy)

    2016-06-30

    Highlights: • We have deposited in vacuum niobium carbide films by fs and ns PLD. • We have compared PLD performed by ultra-short and short laser pulses. • The films deposited by fs PLD of NbC are formed by nanoparticles. • The structure of the films produced by fs PLD at 500 °C corresponds to NbC. - Abstract: NbC crystalline films have been deposited in vacuum by ultra-short pulsed laser deposition technique. The films have been characterized by transmission and scanning electron microscopies and by X-ray diffraction. To clarify the ablation–deposition mechanism, the plasma produced by the ablation process has been characterized by optical emission spectroscopy and fast imaging. A comparison of the results with those obtained by ns pulsed deposition of the same target has been carried out.

  17. Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

    Energy Technology Data Exchange (ETDEWEB)

    Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Bloisi, Francesco, E-mail: bloisi@na.infn.it [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy); Calabria, Raffaela; Califano, Valeria [Istituto Motori – CNR, Naples (Italy); Depero, Laura E. [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, University of Naples “Federico II”, Napoli (Italy); Federici, Stefania [Department of Mechanical and Industrial Engineering, University of Brescia, Brescia (Italy); Massoli, Patrizio [Istituto Motori – CNR, Naples (Italy); Vicari, Luciano R.M. [SPIN – CNR, Naples (Italy); Department of Physics, University of Naples “Federico II”, Napoli (Italy)

    2015-05-01

    Highlights: • A lipase film was deposited with Matrix Assisted Pulsed Laser Evaporation technique. • FTIR spectra show that laser irradiation do not damage lipase molecule. • Laser fluence controls the characteristics of complex structure generated by MAPLE. - Abstract: Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence.

  18. Femtosecond and nanosecond pulsed laser deposition of silicon and germanium

    Energy Technology Data Exchange (ETDEWEB)

    Reenaas, Turid Worren [Department of Physics, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Lee, Yen Sian [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Chowdhury, Fatema Rezwana; Gupta, Manisha; Tsui, Ying Yin [Department of Electrical and Computer Engineering, University of Alberta (Canada); Tou, Teck Yong [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Yap, Seong Ling [Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Kok, Soon Yie [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Yap, Seong Shan, E-mail: seongshan@gmail.com [Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-11-01

    Highlights: • Ge and Si were deposited by fs and ns laser at room temperature and at vacuum. • Ion of 10{sup 4} ms{sup −1} and 30–200 eV was obtained for ns ablation for Ge and Si. • Highly energetic ions of 10{sup 5} ms{sup −1} with 2–7 KeV were produced in fs laser ablation. • Nanocrystalline Si and Ge were deposited by using fs laser. • Nanoparticles < 10 nm haven been obtained by fs laser. - Abstract: 150 fs Ti:Sapphire laser pulsed laser deposition of Si and Ge were compared to a nanosecond KrF laser (25 ns). The ablation thresholds for ns lasers were about 2.5 J cm{sup −2} for Si and 2.1 J cm{sup −2} for Ge. The values were about 5–10 times lower when fs laser were used. The power densities were 10{sup 8}–10{sup 9} W cm{sup −2} for ns but 10{sup 12} W cm{sup −2} for fs. By using an ion probe, the ions emission at different fluence were measured where the emitting ions achieving the velocity in the range of 7–40 km s{sup −1} and kinetic energy in the range of 30–200 eV for ns laser. The ion produced by fs laser was measured to be highly energetic, 90–200 km s{sup −1}, 2–10 KeV. Two ion peaks were detected above specific laser fluence for both ns and fs laser ablation. Under fs laser ablation, the films were dominated by nano-sized crystalline particles, drastically different from nanosecond pulsed laser deposition where amorphous films were obtained. The ions characteristics and effects of pulse length on the properties of the deposited films were discussed.

  19. Stoichiometry controlled oxide thin film growth by pulsed laser deposition

    NARCIS (Netherlands)

    Groenen, Rik; Smit, Jasper; Orsel, Kasper; Vailionis, Arturas; Bastiaens, Bert; Huijben, Mark; Boller, Klaus; Rijnders, Guus; Koster, Gertjan

    2015-01-01

    The oxidation of species in the plasma plume during pulsed laser deposition controls both the stoichiometry as well as the growth kinetics of the deposited SrTiO3 thin films, instead of the commonly assumed mass distribution in the plasma plume and the kinetic energy of the arriving species. It was

  20. RHEED study of titanium dioxide with pulsed laser deposition

    DEFF Research Database (Denmark)

    Rasmussen, Inge Lise; Pryds, Nini; Schou, Jørgen

    2009-01-01

    Reflection high-energy electron diffraction (RHEED) operated at high pressure has been used to monitor the growth of thin films of titanium dioxide (TiO2) on (1 0 0) magnesium oxide (MgO) substrates by pulsed laser deposition (PLD). The deposition is performed with a synthetic rutile TiO2 target...

  1. Characterization of polymer thin films obtained by pulsed laser deposition

    Science.gov (United States)

    Palla-Papavlu, A.; Dinca, V.; Ion, V.; Moldovan, A.; Mitu, B.; Luculescu, C.; Dinescu, M.

    2011-04-01

    The development of laser techniques for the deposition of polymer and biomaterial thin films on solid surfaces in a controlled manner has attracted great attention during the last few years. Here we report the deposition of thin polymer films, namely Polyepichlorhydrin by pulsed laser deposition. Polyepichlorhydrin polymer was deposited on flat substrate (i.e. silicon) using an NdYAG laser (266 nm, 5 ns pulse duration and 10 Hz repetition rate). The obtained thin films have been characterized by atomic force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and spectroscopic ellipsometry. It was found that for laser fluences up to 1.5 J/cm 2 the chemical structure of the deposited polyepichlorhydrin polymer thin layers resembles to the native polymer, whilst by increasing the laser fluence above 1.5 J/cm 2 the polyepichlorohydrin films present deviations from the bulk polymer. Morphological investigations (atomic force microscopy and scanning electron microscopy) reveal continuous polyepichlorhydrin thin films for a relatively narrow range of fluences (1-1.5 J/cm 2). The wavelength dependence of the refractive index and extinction coefficient was determined by ellipsometry studies which lead to new insights about the material. The obtained results indicate that pulsed laser deposition method is potentially useful for the fabrication of polymer thin films to be used in applications including electronics, microsensor or bioengineering industries.

  2. Nanosecond laser-induced phase transitions in pulsed laser deposition-deposited GeTe films

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xinxing, E-mail: xinxing.sun@iom-leipzig.de; Thelander, Erik; Lorenz, Pierre; Gerlach, Jürgen W.; Decker, Ulrich; Rauschenbach, Bernd [Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318, Leipzig (Germany)

    2014-10-07

    Phase transformations between amorphous and crystalline states induced by irradiation of pulsed laser deposition grown GeTe thin films with nanosecond laser pulses at 248 nm and pulse duration of 20 ns are studied. Structural and optical properties of the Ge-Te phase-change films were studied by X-ray diffraction and optical reflectivity measurements as a function of the number of laser pulses between 0 and 30 pulses and of the laser fluence up to 195 mJ/cm². A reversible phase transition by using pulse numbers ≥ 5 at a fluence above the threshold fluence between 11 and 14 mJ/cm² for crystallization and single pulses at a fluence between 162 and 182 mJ/cm² for amorphization could be proved. For laser fluences from 36 up to 130 mJ/cm², a high optical contrast of 14.7% between the amorphous and crystalline state is measured. A simple model is used that allows the discussion on the distribution of temperature in dependency on the laser fluence.

  3. Pulsed laser deposition of metal films and nanoparticles in vacuum using subnanosecond laser pulses.

    Science.gov (United States)

    Ganeev, R A; Chakravarty, U; Naik, P A; Srivastava, H; Mukherjee, C; Tiwari, M K; Nandedkar, R V; Gupta, P D

    2007-03-10

    A study of silver, chromium, stainless-steel, and indium thin films prepared by subnanosecond laser deposition in vacuum is reported. We compare the laser ablation in vacuum at the weak- and tight-focusing conditions of a Ti:sapphire laser beam and analyze the nanoparticles synthesized in the latter case using absorption spectroscopy, x-ray fluorescence, atomic force microscopy, and scanning electron microscopy. Our results show that the nanoparticle formation can be accomplished using long laser pulses under tight-focusing conditions.

  4. Energy deposition from focused terawatt laser pulses in air

    CERN Document Server

    Point, Guillaume; Mysyrowicz, André; Houard, Aurélien

    2015-01-01

    Laser filamentation is responsible for the deposition of a significant part of the laser pulse energy in the propagation medium. We found that using terawatt laser pulses and relatively tight focusing conditions in air, resulting in a bundle of co-propagating multifilaments, more than 50 % of the pulses energy is transferred to the medium, eventually degrading into heat. This results in a strong hydrodynamic reaction of air with the generation of shock waves and associated underdense channels for each short-scale filament. In the focal zone, where filaments are close to each other, these discrete channels eventually merge to form a single cylindrical low-density tube over a $\\sim 1~ \\mu\\mathrm{s}$ timescale. We measured the maximum lineic deposited energy to be more than 1 J/m.

  5. Stabilizing laser energy density on a target during pulsed laser deposition of thin films

    Science.gov (United States)

    Dowden, Paul C.; Jia, Quanxi

    2016-05-31

    A process for stabilizing laser energy density on a target surface during pulsed laser deposition of thin films controls the focused laser spot on the target. The process involves imaging an image-aperture positioned in the beamline. This eliminates changes in the beam dimensions of the laser. A continuously variable attenuator located in between the output of the laser and the imaged image-aperture adjusts the energy to a desired level by running the laser in a "constant voltage" mode. The process provides reproducibility and controllability for deposition of electronic thin films by pulsed laser deposition.

  6. Epitaxial thin films grown by pulsed laser deposition

    NARCIS (Netherlands)

    Blank, D.H.A.

    2005-01-01

    In this paper, we present the pulsed laser deposition (PLD) technique to control the growth of metal oxide materials at atomic level using high-pressure reflective high-energy electron diffraction and ellipsometry. These developments have helped to make PLD a grown-up technique to fabricate complex

  7. Transparent conducting oxides on polymeric substrates by pulsed laser deposition

    NARCIS (Netherlands)

    Dekkers, Jan Matthijn

    2007-01-01

    This thesis describes the research on thin films of transparent conducting oxides (TCOs) on polymeric substrates manufactured by pulsed laser deposition (PLD). TCOs are an indispensable part in optoelectronic applications such as displays, solar cells, light-emitting diodes, etc. At present, in many

  8. Divalent Mn in calcium hydroxyapatite by pulse laser deposition.

    Science.gov (United States)

    Mayer, I; Peto, G; Karacs, A; Molnár, G; Popov, I

    2010-10-01

    Pulse laser deposition (PLD) was used to deposit Mn containing calcium hydroxyapatite (HAMn). The PLD process ensures that the composition of the target and the deposited layer is the same. In some cases additional effort should be made to preserve some volatile components, namely OH. This was ensured by water steam supply. Calcium hydroxyapatite deposited by this method has the same properties as the target in respect to lattice parameters and valence state of Mn, which ensures the fixation between hard tissue and metal implants. This fact makes PLD grown HAMn layer covering implants to be improved for practical use.

  9. Pulsed laser deposition of niobium nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Farha, Ashraf Hassan, E-mail: ahass006@odu.edu; Elsayed-Ali, Hani E., E-mail: helsayed@odu.edu [Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529 (United States); Applied Research Center, Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Department of Physics, Faculty of Science, Ain Shams University, Cairo 11566 (Egypt); Ufuktepe, Yüksel, E-mail: ufuk@cu.edu.tr [Department of Physics, University of Cukurova, 01330 Adana (Turkey); Myneni, Ganapati, E-mail: rao@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

    2015-12-04

    Niobium nitride (NbN{sub x}) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbN{sub x} films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (λ = 1064 nm, ∼40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbN{sub x} films from mixed β-Nb{sub 2}N and cubic δ-NbN phases to single hexagonal β-Nb{sub 2}N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbN{sub x} deposited on Si(100) were also investigated. The NbN{sub x} films exhibited a cubic δ-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbN{sub x} film morphology and phase.

  10. Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

    Science.gov (United States)

    Aronne, Antonio; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Depero, Laura E.; Fanelli, Esther; Federici, Stefania; Massoli, Patrizio; Vicari, Luciano R. M.

    2015-05-01

    Lipase is an enzyme that finds application in biodiesel production and for detection of esters and triglycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial application, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence.

  11. History and current status of commercial pulsed laser deposition equipment

    Science.gov (United States)

    Greer, James A.

    2014-01-01

    This paper will review the history of the scale-up of the pulsed laser deposition (PLD) process from small areas ∼1 cm2 up to 10 m2 starting in about 1987. It also documents the history of commercialization of PLD as various companies become involved in selling fully integrated laser deposition tools starting in 1989. The paper will highlight the current state of the art of commercial PLD equipment for R&D that is available on the market today from mainstream vendors as well as production-oriented applications directed at piezo-electric materials for microelectromechanical systems and high-temperature superconductors for coated-conductor applications. The paper clearly demonstrates that considerable improvements have been made to scaling this unique physical vapour deposition process to useful substrate sizes, and that commercial deposition equipment is readily available from a variety of vendors to address a wide variety of technologically important thin-film applications.

  12. Optical Multichannel Imaging of Pulsed Laser Deposition of ZnO (PostPrint)

    Science.gov (United States)

    2014-08-01

    AFRL-RX-WP-JA-2014-0186 OPTICAL MULTICHANNEL IMAGING OF PULSED LASER DEPOSITION OF ZNO (POSTPRINT) John G. Jones AFRL/RXAN...PULSED LASER DEPOSITION OF ZNO (POSTPRINT) 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR(S...Optical Multichannel Imaging of Pulsed Laser Deposition of ZnO John G. Jones, Lirong Sun, Neil R. Murphy, and Rachel Jakubiak Abstract— Pulsed laser

  13. Pulsed laser deposition and characterization of Alnico5 magnetic films

    Energy Technology Data Exchange (ETDEWEB)

    Butt, M.Z., E-mail: mzbutt49@yahoo.com [Department of Physics, GC University, Lahore 54000 (Pakistan); Ali, Dilawar [Department of Physics, GC University, Lahore 54000 (Pakistan); Ahmad, Fayyaz [Department of Physics, University of Engineering and Technology, Lahore 54890 (Pakistan); Magnetophotonics Research Laboratory, Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2013-09-01

    Alnico5 films were deposited by pulsed laser deposition on glass substrate at room temperature under a vacuum ∼10{sup −3} Torr in the absence and in the presence of 500 Oe external transverse magnetic field applied on the plasma plume during film deposition. For this purpose, Nd:YAG laser was employed to ablate the Alnico5 target. The ablated material was deposited on glass substrate placed at a distance of 2 cm from the target. The structural and magnetic properties of the film were analyzed by X-ray diffraction, atomic force microscope, and vibrating sample magnetometer. X-ray diffraction patterns showed that the Alnico5 films were amorphous in nature. Atomic force microscopy revealed that the Alnico5 film deposited in absence of external magnetic field has larger root-mean-square roughness value (60.2 nm) than the magnetically deposited film (42.9 nm). Vibrating sample magnetometer measurements showed that the in-plane saturation magnetization of Alnico5 film deposited in the presence of external magnetic field increases by 32% as compared to that for the film deposited in the absence of external magnetic field. However, the out-of-plane saturation magnetization was almost independent of the external magnetic field. In magnetically deposited film, there is in-plane anisotropy parallel to the applied external magnetic field.

  14. Pulsed laser deposition and characterisation of thin superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Morone, A. [CNR, zona industriale di Tito Scalo, Potenza (Italy). Istituto per i Materiali Speciali

    1996-09-01

    Same concepts on pulsed laser deposition of thin films will be discussed and same examples of high transition temperature (HTc) BiSrCaCuO (BISCO) and low transition temperature NbN/MgO/NbN multilayers will be presented. X-ray and others characterizations of these films will be reported and discussed. Electrical properties of superconducting thin films will be realized as a function of structural and morphological aspect.

  15. Pulsed laser deposition for the synthesis of monolayer WSe2

    Science.gov (United States)

    Mohammed, A.; Nakamura, H.; Wochner, P.; Ibrahimkutty, S.; Schulz, A.; Müller, K.; Starke, U.; Stuhlhofer, B.; Cristiani, G.; Logvenov, G.; Takagi, H.

    2017-08-01

    Atomically thin films of WSe2 from one monolayer up to 8 layers were deposited on an Al2O3 r-cut ( 1 1 ¯ 02 ) substrate using a hybrid-Pulsed Laser Deposition (PLD) system where a laser ablation of pure W is combined with a flux of Se. Specular X-ray reflectivities of films were analysed and were consistent with the expected thickness. Raman measurement and atomic force microscopy confirmed the formation of a WSe2 monolayer and its spatial homogeneity over the substrate. Grazing-incidence X-ray diffraction uncovered an in-plane texture in which WSe2 [ 10 1 ¯ 0 ] preferentially aligned with Al2O3 [ 11 2 ¯ 0 ]. These results present a potential to create 2D transition metal dichalcogenides by PLD, where the growth kinetics can be steered in contrast to common growth techniques like chemical vapor deposition and molecular beam epitaxy.

  16. State-of-the-art Pb photocathodes deposited by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gontad, F., E-mail: Francisco.gontad@le.infn.it; Perrone, A.

    2014-05-21

    In this article we present and discuss the current status of thin film Pb photocathodes deposited by pulsed laser deposition (PLD) with different laser parameters, such as laser fluence, wavelength or pulse duration. The PLD technique appears very efficient for the fabrication of pure Pb photocathodes, providing good adherence and respectable quantum efficiency. The films deposited on the picosecond and subpicosecond regimes are practically free of big droplets and fragments, whereas in the nanosecond regime their presence cannot be neglected. All the films present a granular structure and polycrystalline character with preferential orientation along the (111) crystalline planes, irrespective of the laser pulse duration or wavelength. The main results obtained from the photoemission performance of Pb thin films deposited by PLD demonstrate their chemical stability under vacuum conditions and respectable quantum efficiency with a maximum of 7.3×10{sup −5} for films deposited on the subpicosecond regime. The photoemission properties confirm that Pb thin films deposited by PLD are a notable alternative for the fabrication of photocathodes for superconductive radio-frequency electron guns. - Highlights: • Lead samples were grown by Pulsed Laser Deposition at different laser parameters • All films present a granular morphology • Lead films grow preferentially along the 111 crystalline planes of the cubic net • A maximum quantum efficiency of 7.3 × 10-5 has been found.

  17. ZnO thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tsoutsouva, M.G. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Papadimitriou, D. [National Technical University of Athens, Department of Physics, GR-15780 Athens (Greece); Fasaki, I.; Kompitsas, M. [Theor. and Phys./Chem. Institute, National Hellenic Research Foundation, 48 Vas. Konstantinou Ave., 11635 Athens (Greece)

    2011-04-15

    Zinc oxide (ZnO) thin films were deposited on soda lime glass substrates by pulsed laser deposition (PLD) in an oxygen-reactive atmosphere. The structural, optical, and electrical properties of the as-prepared thin films were studied in dependence of substrate temperature and oxygen pressure. High quality polycrystalline ZnO films with hexagonal wurtzite structure were deposited at substrate temperatures of 100 and 300 deg. C. The RMS roughness of the deposited oxide films was found to be in the range 2-9 nm and was only slightly dependent on substrate temperature and oxygen pressure. Electrical measurements indicated a decrease of film resistivity with the increase of substrate temperature and the decrease of oxygen pressure. The ZnO films exhibited high transmittance of 90% and their energy band gap and thickness were in the range 3.26-3.30 eV and 256-627 nm, respectively.

  18. The spatial thickness distribution of metal films produced by large area pulsed laser deposition

    DEFF Research Database (Denmark)

    Pryds, Nini; Schou, Jørgen; Linderoth, Søren

    2007-01-01

    Thin films of metals have been deposited in the large-area Pulsed Laser Deposition (PLD) Facility at Riso National Laboratory. Thin films of Ag and Ni were deposited with laser pulses from an excimer laser at 248 nm with a rectangular beam spot at a fluence of 10 J/cm(2) on glass substrates of 12...

  19. Picosecond and subpicosecond pulsed laser deposition of Pb thin films

    Directory of Open Access Journals (Sweden)

    F. Gontad

    2013-09-01

    Full Text Available Pb thin films were deposited on Nb substrates by means of pulsed laser deposition (PLD with UV radiation (248 nm, in two different ablation regimes: picosecond (5 ps and subpicosecond (0.5 ps. Granular films with grain size on the micron scale have been obtained, with no evidence of large droplet formation. All films presented a polycrystalline character with preferential orientation along the (111 crystalline planes. A maximum quantum efficiency (QE of 7.3×10^{-5} (at 266 nm and 7 ns pulse duration was measured, after laser cleaning, demonstrating good photoemission performance for Pb thin films deposited by ultrashort PLD. Moreover, Pb thin film photocathodes have maintained their QE for days, providing excellent chemical stability and durability. These results suggest that Pb thin films deposited on Nb by ultrashort PLD are a noteworthy alternative for the fabrication of photocathodes for superconductive radio-frequency electron guns. Finally, a comparison with the characteristics of Pb films prepared by ns PLD is illustrated and discussed.

  20. Exploring the deposition of oxides on silicon for photovoltaic cells by pulsed laser deposition

    NARCIS (Netherlands)

    Doeswijk, Lianne M.; Moor, de Hugo H.C.; Rogalla, Horst; Blank, Dave H.A.

    2002-01-01

    Since most commercially available solar cells are still made from silicon, we are exploring the introduction of passivating qualities in oxides, with the potential to serve as an antireflection coating. Pulsed laser deposition (PLD) was used to deposit TiO2 and SrTiO3 coatings on silicon substrates.

  1. Pulsed laser deposition of fluoride glass thin films

    Science.gov (United States)

    Ganser, Dimitri; Gottmann, Jens; Mackens, Uwe; Weichmann, Ulrich

    2010-11-01

    The development of integrated waveguide lasers for different applications such as marking, illumination or medical technology has become highly desirable. Diode pumped planar waveguide lasers emitting in the green visible spectral range, e.g. thin films from praseodymium doped fluorozirconate glass matrix (called ZBLAN, owing to the main components ZrF 4, BaF 2, LaF 3, AlF 3 and NaF) as the active material pumped by a blue laser diode, have aroused great interest. In this work we have investigated the deposition of Pr:ZBLAN thin films using pulsed laser radiation of λ = 193 and λ = 248 nm. The deposition has been carried out on MgF 2 single crystal substrates in a vacuum chamber by varying both processing gas pressure and energy fluence. The existence of an absorption line at 210 nm in Pr:ZBLAN leads to absorption and radiative relaxation of the absorbed laser energy of λ = 193 nm preventing the evaporation of target material. The deposited thin films consist of solidified and molten droplets and irregular particulates only. Furthermore, X-ray radiation has been applied to fluoride glass targets to enhance the absorption in the UV spectral region and to investigate the deposition of X-ray treated targets applying laser radiation of λ = 248 nm. It has been shown that induced F-centres near the target surface are not thermally stable and can be easily ablated. Therefore, λ = 248 nm is not suitable for evaporation of Pr:ZBLAN.

  2. Pulsed laser deposition of fluoride glass thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ganser, Dimitri, E-mail: dimitri.ganser@llt.rwth-aachen.de [Chair for Laser Technology LLT, RWTH Aachen University, Steinbachstr. 15, D-52074 Aachen (Germany); Gottmann, Jens [Chair for Laser Technology LLT, RWTH Aachen University, Steinbachstr. 15, D-52074 Aachen (Germany); Mackens, Uwe; Weichmann, Ulrich [Philips Research Laboratories, Weisshausstrasse 2, D-52066 Aachen (Germany)

    2010-11-15

    The development of integrated waveguide lasers for different applications such as marking, illumination or medical technology has become highly desirable. Diode pumped planar waveguide lasers emitting in the green visible spectral range, e.g. thin films from praseodymium doped fluorozirconate glass matrix (called ZBLAN, owing to the main components ZrF{sub 4}, BaF{sub 2}, LaF{sub 3}, AlF{sub 3} and NaF) as the active material pumped by a blue laser diode, have aroused great interest. In this work we have investigated the deposition of Pr:ZBLAN thin films using pulsed laser radiation of {lambda} = 193 and {lambda} = 248 nm. The deposition has been carried out on MgF{sub 2} single crystal substrates in a vacuum chamber by varying both processing gas pressure and energy fluence. The existence of an absorption line at 210 nm in Pr:ZBLAN leads to absorption and radiative relaxation of the absorbed laser energy of {lambda} = 193 nm preventing the evaporation of target material. The deposited thin films consist of solidified and molten droplets and irregular particulates only. Furthermore, X-ray radiation has been applied to fluoride glass targets to enhance the absorption in the UV spectral region and to investigate the deposition of X-ray treated targets applying laser radiation of {lambda} 248 nm. It has been shown that induced F-centres near the target surface are not thermally stable and can be easily ablated. Therefore, {lambda} = 248 nm is not suitable for evaporation of Pr:ZBLAN.

  3. Stoichiometric magnetite grown by infrared nanosecond pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Mikel, E-mail: mikel.sanz@iqfr.csic.es [Instituto de Química Física Rocasolano, CSIC, 28006 Madrid (Spain); Oujja, Mohamed; Rebollar, Esther; Marco, José F.; Figuera, Juan de la; Monti, Matteo [Instituto de Química Física Rocasolano, CSIC, 28006 Madrid (Spain); Bollero, Alberto [IMDEA Nanoscience, Instituto Madrileño de Estudios Avanzados en Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid (Spain); Camarero, Julio [IMDEA Nanoscience, Instituto Madrileño de Estudios Avanzados en Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid (Spain); Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera, Campus Universidad Autónoma de Madrid, 28049 Madrid (Spain); Pedrosa, Francisco J. [IMDEA Nanoscience, Instituto Madrileño de Estudios Avanzados en Nanociencia, Campus Universidad Autónoma de Madrid, 28049 Madrid (Spain); García-Hernández, Mar [Instituto de Ciencias Materiales de Madrid, CSIC, 28049 Madrid (Spain); Castillejo, Marta [Instituto de Química Física Rocasolano, CSIC, 28006 Madrid (Spain)

    2013-10-01

    Pulsed laser deposition (PLD) is a versatile technique for the fabrication of nanostructures due to the possibilities it offers to control size and shape of nanostructured deposits by varying the laser parameters. Magnetite nanostructures are currently promising materials to be used in computing, electronic devices and spintronic applications. For all these uses the fabrication of uniform nanostructured pure magnetite thin films is highly advantageous. In PLD of magnetite, the laser irradiation wavelength and substrate temperature crucially affect the composition, crystallinity, surface structure and the magnetic properties of the grown samples. This work shows that the use of nanosecond IR laser at 1064 nm enhances the quality of the resulting magnetite thin films, compared to the extensively used UV wavelengths. Deposition at 1064 nm, upon heating the substrate at 750 K, produces thin films constituted by stoichiometric magnetite nanoparticles with sharp edges and sizes ranging from 80 to 150 nm, with a Verwey transition at 119 K and a coercivity of 232 Oe at room temperature, close to those of pure bulk magnetite. Thus, IR-PLD of self-prepared hematite sintered targets constitutes a low-cost procedure of fabrication of pure magnetite nanostructured thin films.

  4. Laser cleaning of pulsed laser deposited rhodium films for fusion diagnostic mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Uccello, A., E-mail: andrea.uccello@mail.polimi.it [Dipartimento di Energia, Politecnico di Milano, Milan (Italy); Maffini, A., E-mail: alessandro.maffini@mail.polimi.it [Dipartimento di Energia, Politecnico di Milano, Milan (Italy); Dellasega, D., E-mail: david.dellasega@polimi.it [Dipartimento di Energia, Politecnico di Milano, Milan (Italy); Istituto di Fisica del Plasma, Consiglio Nazionale delle Ricerche, EURATOM-ENEA-CNR Association, Milan (Italy); Passoni, M., E-mail: matteo.passoni@polimi.it [Dipartimento di Energia, Politecnico di Milano, Milan (Italy); Istituto di Fisica del Plasma, Consiglio Nazionale delle Ricerche, EURATOM-ENEA-CNR Association, Milan (Italy)

    2013-10-15

    Highlights: ► Pulsed laser deposition is exploited to produce Rh films for first mirrors. ► Pulsed laser deposition is exploited to produce tokamak-like C contaminants. ► Rh laser damage threshold has been evaluated for infrared pulses. ► Laser cleaning of C contaminated Rh films gives promising results. -- Abstract: In this paper an experimental investigation on the laser cleaning process of rhodium films, potentially candidates to be used as tokamak first mirrors (FMs), from redeposited carbon contaminants is presented. A relevant issue that lowers mirror's performance during tokamak operations is the redeposition of sputtered material from the first wall on their surface. Among all the possible techniques, laser cleaning, in which a train of laser pulses is launched to the surface that has to be treated, is a method to potentially mitigate this problem. The same laser system (Q-switched Nd:YAG laser with a fundamental wavelength of 1064-nm and 7-ns pulses) has been employed with three aims: (i) production by pulsed laser deposition (PLD) of Rh film mirrors, (ii) production by PLD of C deposits with controlled morphology, and (iii) investigation of the laser cleaning method onto C contaminated Rh samples. The evaluation of Rh films laser damage threshold, as a function of fluence and number of pulses, is discussed. Then, the C/Rh films have been cleaned by the laser beam. The exposed zones have been characterized by visual inspection and scanning electron microscopy (SEM), showing promising results.

  5. Aluminosilicate glass thin films elaborated by pulsed laser deposition

    Science.gov (United States)

    Carlier, Thibault; Saitzek, Sébastien; Méar, François O.; Blach, Jean-François; Ferri, Anthony; Huvé, Marielle; Montagne, Lionel

    2017-03-01

    In the present work, we report the elaboration of aluminosilicate glass thin films by Pulsed Laser Deposition at various temperatures deposition. The amorphous nature of glass thin films was highlighted by Grazing Incidence X-Ray Diffraction and no nanocristallites were observed in the glassy matrix. Chemical analysis, obtained with X-ray Photoelectron Spectroscopy and Time of Flight Secondary Ion Mass Spectroscopy, showed a good transfer and homogeneous elementary distribution with of chemical species from the target to the film a. Structural studies performed by Infrared Spectroscopy showed that the substrate temperature plays an important role on the bonding configuration of the layers. A slight shift of Si-O modes to larger wavenumber was observed with the synthesis temperature, assigned to a more strained sub-oxide network. Finally, optical properties of thins film measured by Spectroscopic Ellipsometry are similar to those of the bulk aluminosilicate glass, which indicate a good deposition of aluminosilicate bulk glass.

  6. Thermochromic VO2 on Zinnwaldite Mica by pulsed laser deposition

    Science.gov (United States)

    Mathevula, L.; Ngom, B. D.; Kotsedi, L.; Sechogela, P.; Doyle, T. B.; Ghouti, M.; Maaza, M.

    2014-09-01

    VO2 thin films have been deposited by pulsed laser deposition on Zinnwaldite Mica substrates. The crystal structure, chemical composition, morphology were determined and the semiconductor/metal transition (SMT) properties of the deposited films were investigated. Without any post annealing, the films exhibit a textured nature with a VO2 (0 1 1) preferred crystallographic orientation and an elevated thermal variation of the electric resistance ratio RS/RM through the SMT at T ≈ 68 °C of the order of 104 and a narrow ∼7 °C hysteresis. In addition, the growth of the VO2 crystallites seem to be governed likely by a Volmer-Weber or Stranski-Krastanov mechanisms and certainly not a Frank-van Der Merwe process.

  7. Property improvement of pulsed laser deposited boron carbide films by pulse shortening

    Energy Technology Data Exchange (ETDEWEB)

    Csako, T. [Department of Optics and Quantum Electronics, University of Szeged, P.O. Box 406, H-6701 Szeged (Hungary); Budai, J. [Department of Optics and Quantum Electronics, University of Szeged, P.O. Box 406, H-6701 Szeged (Hungary); Szoerenyi, T. [Research Group on Laser Physics of the Hungarian Academy of Sciences, University of Szeged, P.O. Box 406, H-6701 Szeged (Hungary)]. E-mail: t.szorenyi@physx.u-szeged.hu

    2006-04-30

    Growth characteristics and surface morphology of boron carbide films fabricated by ablating a B{sub 4}C target in high vacuum with a traditional KrF excimer laser and a high brightness hybrid dye/excimer laser system emitting at the same wavelength while delivering 700 fs pulses are compared. The ultrashort pulse processing is highly effective. Energy densities between 0.25 and 2 J cm{sup -2} result in apparent growth rates ranging from 0.017 to 0.085 nm/pulse. Ablation with nanosecond pulses of one order of magnitude higher energy densities yields smaller growth rates, the figures increase from 0.002 to 0.016 nm/pulse within the 2-14.3 J cm{sup -2} fluence window. 2D thickness maps derived from variable angle spectroscopic ellipsometry reveal that, when ablating with sub-ps pulses, the spot size rather than the energy density determines both the deposition rate and the angular distribution of film material. Pulse shortening leads to significant improvement in surface morphology, as well. While droplets with number densities ranging from 1 x 10{sup 4} to 7 x 10{sup 4} mm{sup -2} deteriorate the surface of the films deposited by the KrF excimer laser, sub-ps pulses produce practically droplet-free films. The absence of droplets has also a beneficial effect on the stoichiometry and homogeneity of the films fabricated by ultrashort pulses.

  8. Effects of laser fluence on the structural properties of pulsed laser deposited ruthenium thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wai-Keat; Wong, Hin-Yong; Chan, Kah-Yoong; Tou, Teck-Yong [Multimedia University, Centre for Advanced Devices and Systems (CADS), Faculty of Engineering, Cyberjaya, Selangor (Malaysia); Yong, Thian-Khok [Universiti Tunku Abdul Rahman, Faculty of Engineering and Science, Setapak, Kuala Lumpur (Malaysia); Yap, Seong-Shan [Norwegian University of Science and Technology, Institute of Physics, Trondheim (Norway)

    2010-08-15

    Ruthenium (Ru) has received great interest in recent years for applications in microelectronics. Pulsed laser deposition (PLD) enables the growth of Ru thin films at low temperatures. In this paper, we report for the first time the characterization of pulsed laser deposited Ru thin films. The deposition processes were carried out at room temperature in vacuum environment for different durations with a pulsed Nd:YAG laser of 355-nm laser wavelength, employing various laser fluences ranging from 2 J/cm{sup 2} to 8 J/cm{sup 2}. The effect of the laser fluence on the structural properties of the deposited Ru films was investigated using surface profilometry, scanning electron microscopy (SEM), and X-ray diffraction (XRD). Ru droplets, some spherical in shape and some flattened into round discs were found on the deposited Ru. The droplets were correlated to ripple formations on the target during the laser-induced ejection from the target. In addition, crystalline Ru with orientations of (100), (101), and (002) was observed in the XRD spectra and their intensities were found to increase with increasing laser fluence and film thickness. Grain sizes ranging from 20 nm to 35 nm were deduced using the Scherrer formula. Optical emission spectroscopy (OES) and energy-dispersive X-ray spectroscopy (EDS) show that the composition of the plume and the deposited Ru film was of high purity. (orig.)

  9. Growth of tantalum pentoxide film by pulsed laser deposition

    Science.gov (United States)

    Zhang, Jun-Ying; Fang, Qi; Boyd, Ian W.

    1999-01-01

    Thin films of Ta 2O 5 have been deposited on quartz and silicon substrates by 532-nm (Nd:YAG) pulsed laser deposition (PLD) in various O 2 gas environments. The influence of the deposition parameters, such as oxygen pressure, substrate temperature and annealing under UV irradiation using a 172-nm excimer lamp, on the properties of the grown films, has been studied. The refractive index of the films increases with increasing pressure of O 2. X-ray diffraction measurements show that the as-deposited films are amorphous at temperatures below 500°C and possess orthorhombic (β-Ta 2O 5) crystal structure at temperatures above 600°C. The optical properties determined by UV spectrophotometry also strongly depend on the deposition parameters. At O 2 pressures above 0.15 mbar, the refractive index of the films was about 2.12 which is close to the bulk Ta 2O 5 value of 2.2. Optical transmittance around 85% in the visible region of the spectrum was obtained at an oxygen pressure of 0.2 mbar.

  10. Laser surface modification of titanium substrate for pulsed laser deposition of highly adherent hydroxyapatite.

    Science.gov (United States)

    Rajesh, P; Muraleedharan, C V; Komath, Manoj; Varma, Harikrishna

    2011-07-01

    Biomedical implant devices made out of titanium and its alloys are benefited by a modified surface or a bioactive coating to enhance bone bonding ability and to function effectively in vivo for the intended period of time. In this respect hydroxyapatite coating developed through pulsed laser deposition is a promising approach. Since the success of the bioactive ceramic coated implant depends mainly on the substrate-coating strength; an attempt has been made to produce micro patterned surface structure on titanium substrate for adherent hydroxyapatite coating. A pulsed Nd-YAG laser beam (355 nm) with 10 Hz repetition rate was used for surface treatment of titanium as well as hydroxyapatite deposition. The unfocussed laser beam was used to modify the substrate surface with 500-18,000 laser pulses while keeping the polished substrate in water. Hydroxyapatite deposition was done in a vacuum deposition chamber at 400 °C with the focused laser beam under 1 × 10⁻³ mbar oxygen pressure. Deposits were analyzed to understand the physico-chemical, morphological and mechanical characteristics. The obtained substrate and coating surface morphology indicates that laser treatment method can provide controlled micro-topography. Scratch test analysis and microindentation hardness values of coating on laser treated substrate indicate higher mechanical adhesion with respect to coatings on untreated substrates.

  11. Iridium thin films deposited via pulsed laser deposition for future applications as transition-edge sensors

    Energy Technology Data Exchange (ETDEWEB)

    Galeazzi, M. E-mail: galeazzi@physics.miami.edu; Chen, C.; Cohn, J.L.; Gundersen, J.O

    2004-03-11

    The University of Miami has recently started developing and studying high-resolution microcalorimeters operating near 100 mK for X-ray and particle physics and astrophysics. These detectors will be based on Transition Edge Sensors technology fabricated using iridium thin films deposited via the Pulsed Laser Deposition technique. We report here the preliminary result of the room temperature characterization of the Ir thin films, and an overview of future plans to use the films as transition edge sensors.

  12. Reactive pulsed laser deposition of gold nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Caricato, A.P. [University of Salento, Department of Physics, 73100 Lecce (Italy); Fernandez, M. [University of Salento, Department of Physics, 73100 Lecce (Italy); Leggieri, G. [University of Salento, Department of Physics, 73100 Lecce (Italy)]. E-mail: leggieri@le.infn.it; Luches, A. [University of Salento, Department of Physics, 73100 Lecce (Italy); Martino, M. [University of Salento, Department of Physics, 73100 Lecce (Italy); Romano, F. [University of Salento, Department of Physics, 73100 Lecce (Italy); Tunno, T. [University of Salento, Department of Physics, 73100 Lecce (Italy); Valerini, D. [University of Salento, Department of Physics, 73100 Lecce (Italy); Verdyan, A. [Science Department, Holon Academic Institute of Technology, Holon 58102 (Israel); Soifer, Y.M. [Science Department, Holon Academic Institute of Technology, Holon 58102 (Israel); Azoulay, J. [Science Department, Holon Academic Institute of Technology, Holon 58102 (Israel); Meda, L. [IGD Polimeri Europa S.p.A, Novara (Italy)

    2007-07-31

    We report on the growth and characterization of gold nitride thin films on Si <1 0 0> substrates at room temperature by reactive pulsed laser ablation. A pure (99.95%) Au target was ablated with KrF excimer laser pulses in nitrogen containing atmosphere (N{sub 2} or NH{sub 3}). The gas ambient pressure was varied in the range 0.1-100 Pa. The morphology of the films was studied by using optical, scanning electron and atomic force microscopy, evidencing compact films with RMS roughness in the range 3.6-35.1 nm, depending on the deposition pressure. Rutherford backscattering spectrometry and energy dispersion spectroscopy (EDS) were used to detect the nitrogen concentration into the films. The EDS nitrogen peak does not decrease in intensity after 2 h annealing at 250 deg. C. Film resistivity was measured using a four-point probe and resulted in the (4-20) x 10{sup -8} {omega} m range, depending on the ambient pressure, to be compared with the value 2.6 x 10{sup -8} {omega} m of a pure gold film. Indentation and scratch measurements gave microhardness values of 2-3 GPa and the Young's modulus close to 100 GPa. X-ray photoemission spectra clearly showed the N 1s peak around 400 eV and displaced with respect to N{sub 2} phase. All these measurements point to the formation of the gold nitride phase.

  13. Reactive pulsed laser deposition of gold nitride thin films

    Science.gov (United States)

    Caricato, A. P.; Fernàndez, M.; Leggieri, G.; Luches, A.; Martino, M.; Romano, F.; Tunno, T.; Valerini, D.; Verdyan, A.; Soifer, Y. M.; Azoulay, J.; Meda, L.

    2007-07-01

    We report on the growth and characterization of gold nitride thin films on Si substrates at room temperature by reactive pulsed laser ablation. A pure (99.95%) Au target was ablated with KrF excimer laser pulses in nitrogen containing atmosphere (N 2 or NH 3). The gas ambient pressure was varied in the range 0.1-100 Pa. The morphology of the films was studied by using optical, scanning electron and atomic force microscopy, evidencing compact films with RMS roughness in the range 3.6-35.1 nm, depending on the deposition pressure. Rutherford backscattering spectrometry and energy dispersion spectroscopy (EDS) were used to detect the nitrogen concentration into the films. The EDS nitrogen peak does not decrease in intensity after 2 h annealing at 250 °C. Film resistivity was measured using a four-point probe and resulted in the (4-20) × 10 -8 Ω m range, depending on the ambient pressure, to be compared with the value 2.6 × 10 -8 Ω m of a pure gold film. Indentation and scratch measurements gave microhardness values of 2-3 GPa and the Young's modulus close to 100 GPa. X-ray photoemission spectra clearly showed the N 1s peak around 400 eV and displaced with respect to N 2 phase. All these measurements point to the formation of the gold nitride phase.

  14. Effects of an external magnetic field in pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, T. [Universidad Autonoma de la Ciudad de Mexico (UACM), Prolongacion San Isidro 151, Col. San Lorenzo Tezonco, C.P. 09790, Mexico DF (Mexico)], E-mail: tupacgarcia@yahoo.com; Posada, E. de [CINVESTAV-IPN Unidad Merida, Applied Physics Department, A.P. 73, Cordemex, C.P. 97130 Merida, Yuc. (Mexico); Villagran, M. [CCADET, Universidad Nacional Autonoma de Mexico (UNAM), A.P. 70-186, C.P. 04510, Mexico DF (Mexico); Ll, J.L. Sanchez [Laboratorio de Magnetismo, Facultad de Fisica-IMRE, Universidad de La Habana, La Habana 10400 (Cuba); Bartolo-Perez, P.; Pena, J.L. [CINVESTAV-IPN Unidad Merida, Applied Physics Department, A.P. 73, Cordemex, C.P. 97130 Merida, Yuc. (Mexico)

    2008-12-30

    Thin films were grown by pulsed laser deposition, PLD, on Si (1 0 0) substrates by the ablation of a sintered ceramic SrFe{sub 12}O{sub 19} target with and without the presence of a nonhomogeneous magnetic field of {mu}{sub 0}H = 0.4 T perpendicular to substrate plane and parallel to the plasma expansion axis. The field was produced by a rectangular-shaped Nd-Fe-B permanent magnet and the substrate was just placed on the magnet surface (Aurora method). An appreciable increment of optical emission due to the presence of the magnetic field was observed, but no film composition change or thickness increment was obtained. It suggests that the increment of the optical emission is due mainly to the electron confinement rather than confinement of ionic species.

  15. Pulsed laser deposition of nano-glassy carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Ossi, P.M. [Dip. Ingegneria Nucleare and Centre of Excellence, NanoEngineered Materials and Surfaces (NEMAS), Politecnico di Milano, via Ponzio, 34-3, 20133 Milan (Italy)]. E-mail: paolo.ossi@polimi.it; Bottani, C.E. [Dip. Ingegneria Nucleare and Centre of Excellence, NanoEngineered Materials and Surfaces (NEMAS), Politecnico di Milano, via Ponzio, 34-3, 20133 Milan (Italy); Miotello, A. [Dip. Fisica, Universita di Trento, 38050 Povo (TN) (Italy)

    2005-07-30

    Carbon films have been deposited at room temperature on (1 0 0) Si substrates by pulsed laser ablation (PLA) from a highly oriented pyrolitic graphite source. Changing the laser power density from 8.5 to 19 MW mm{sup -2} and using various ambient atmospheres (helium, argon from 0.6 Pa to 2 kPa), nano-sized cluster-assembled films were obtained. Scanning electron microscopy shows that the film morphology, changes with increasing ambient gas pressure. We observed in the sequence: dense columns, node-like morphology, platelets (only in argon) and an open dendritic structure. By atomic force microscopy, on representative films, we evaluated the size distribution and relative abundancy of aggregates of carbon clusters, as well as film roughness. Raman spectroscopy shows that all the films are sp{sup 2} coordinated, structurally disordered and belong to the family of carbon nano-glasses. The estimated film coherence length gives an average size of about 5 nm for the agglomerated carbon clusters in the films. The average number of carbon atoms per cluster depends on ambient gas pressure, but is nearly independent of laser intensity.

  16. Properties of pulsed laser deposited NiO/MWCNT thin films

    CSIR Research Space (South Africa)

    Yalisi, B

    2011-05-01

    Full Text Available Pulsed laser deposition (PLD) is a thin-film deposition technique, which uses short and intensive laser pulses to evaporate target material. The technique has been used in this work to produce selective solar absorber (SSA) thin film composites...

  17. Epitaxial yttrium iron garnet films grown by pulsed laser deposition

    Science.gov (United States)

    Dorsey, P. C.; Bushnell, S. E.; Seed, R. G.; Vittoria, C.

    1993-07-01

    Epitaxial Y3Fe5O12 (YIG) films have been grown by the pulsed laser deposition (PLD) technique on (111) gadolinium gallium garnet substrates. The effect of substrate temperature and oxygen partial pressure on the structure, composition, and magnetic properties of the films was investigated and compared to liquid phase epitaxy YIG films. The results demonstrated that epitaxial YIG films could be prepared under a wide range of deposition conditions, but narrow linewidth (ΔH≂1 Oe) films were producible only at low oxygen partial pressures (O2temperatures (Ts≳800 °C). Since the linewidth of single-crystal YIG is dominated by surface and volume defects and/or impurities, the narrow linewidth indicated that PLD is a viable technique for producing high-quality ferrite films for microwave device applications. In addition, under all deposition conditions (50-1000 mTorr and 700-850 °C) there is a uniaxial axis perpendicular to the film plane. However, at low oxygen pressure the uniaxial anisotropy energy constant Ku is negative while at high oxygen pressure Ku is positive.

  18. Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Como, N. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Martinez-Landeros, V. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Mejia, I. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Aguirre-Tostado, F.S. [Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Nascimento, C.D.; Azevedo, G. de M; Krug, C. [Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91509-900 (Brazil); Quevedo-Lopez, M.A., E-mail: mquevedo@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States)

    2014-01-01

    The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10{sup −1} to 10{sup 4} Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 10{sup 19} to 10{sup 13} cm{sup −3} and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm{sup 2}/V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 10{sup 19} to 10{sup 13} cm{sup −3}. • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied.

  19. Laser energy density, structure and properties of pulsed-laser deposited zinc oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Tsoutsouva, M.G.; Panagopoulos, C.N. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, Athens 15780 (Greece); Kompitsas, M., E-mail: mcomp@eie.gr [National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute, Vasileos Konstantinou Ave. 48, Athens 11635 (Greece)

    2011-05-01

    Zinc oxide thin films were deposited on soda lime glass substrates by pulsed laser deposition in an oxygen-reactive atmosphere at 20 Pa and a constant substrate temperature at 300 deg. C. A pulsed KrF excimer laser, operated at 248 nm with pulse duration 10 ns, was used to ablate the ceramic zinc oxide target. The structure, the optical and electrical properties of the as-deposited films were studied in dependence of the laser energy density in the 1.2-2.8 J/cm{sup 2} range, with the aid of X-ray Diffraction, Atomic Force Microscope, Transmission Spectroscopy techniques, and the Van der Pauw method, respectively. The results indicated that the structural and optical properties of the zinc oxide films were improved by increasing the laser energy density of the ablating laser. The surface roughness of the zinc oxide film increased with the decrease of laser energy density and both the optical bang gap and the electrical resistivity of the film were significantly affected by the laser energy density.

  20. Scaling in film growth by pulsed laser deposition and modulated beam deposition.

    Science.gov (United States)

    Lee, Sang Bub

    2011-04-01

    The scalings in film growth by pulsed laser deposition (PLD) and modulated beam deposition (MBD) were investigated by Monte Carlo simulations. In PLD, an atomic pulse beam with a period t(0) were deposited instantaneously on a substrate, whereas in MBD, adatoms were deposited during a short time interval t(1) (0≤t(1)≤t(0)) within each period. If t(1)=0, MBD will be identical to PLD and, if t(1)=t(0), MBD will become usual molecular beam epitaxy (MBE). Specifically, logarithmic scaling was investigated for the nucleation density reported for PLD, and the scaling of island density was studied regarding the growth for 0MBE growth was observed as t(1) increased. The phase diagram was also presented.

  1. Manufacturing of Er:ZBLAN ridge waveguides by pulsed laser deposition and ultrafast laser micromachining for green integrated lasers

    Energy Technology Data Exchange (ETDEWEB)

    Gottmann, Jens [Lehrstuhl fuer Lasertechnik, RWTH Aachen University, Steinbachstr. 15, 52074 Aachen (Germany)], E-mail: jens.gottmann@llt.rwth-aachen.de; Moiseev, Leonid; Vasilief, Ion; Wortmann, Dirk [Lehrstuhl fuer Lasertechnik, RWTH Aachen University, Steinbachstr. 15, 52074 Aachen (Germany)

    2008-01-15

    Laser radiation is used both for the deposition of the laser active thin films and for the microstructuring to define wave guiding structures for the fabrication of waveguide lasers. Thin films of Er:ZBLAN (a fluoride glass consisting of ZrF{sub 4}, BaF{sub 2}, LaF{sub 3}, AlF{sub 3}, NaF, ErF{sub 3}) for green up-conversion lasers (545 nm) are produced by pulsed laser deposition using ArF excimer laser radiation (wavelength 193 nm). Manufacturing of the laser active waveguides by microstructuring is done using fs-laser ablation of the deposited films. The structural and optical properties of the films and the damping losses of the structured waveguides are determined in view of the design and the fabrication of compact and efficient diode pumped waveguide lasers. The resulting waveguides are polished, provided with resonator mirrors, pumped using diode lasers and characterized.

  2. In situ X-ray diffraction during pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Vonk, Vedran [Max-Planck-Institute for Metals Research, Stuttgart (Germany); Huijben, Mark [University of California, Berkeley (United States); Driessen, Kurt; Rijnders, Guus; Blank, Dave; Harkema, Sybolt [University of Twente, Enschede (Netherlands); Graafsma, Heinz [Deutsches Elektronen- Synchrotron, Hamburg (Germany)

    2007-07-01

    The use of in situ X-ray diffraction for the study of thin film growth enables in a straightforward way to derive the atomic structure, because the kinematical scattering approximation holds. Here we present the results of studying the heteroepitaxial growth by Pulsed Laser Deposition of complex oxides such as the High-T c superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x} and the insulator LaAlO{sub 3} on SrTiO{sub 3}(001) substrates. A special sample chamber has been constructed to be used with synchrotron X-rays. Detailed pictures of the growth kinetics and of the atomic interface structure at deposition conditions result from fitting quantitatively both the intensity growth oscillations and the crystal truncation rods. The growth of the complex oxide thin films presented here is characterized by substantial interlayer-mass transport and large deviations from the bulk room-temperature atomic structure. The results show the effects of the interplay between formation and diffusion energies on the processes of nucleation and kinetics during heteroepitaxial growth.

  3. Pulsed laser deposition of carbon nanotube and polystyrene-carbon nanotube composite thin films

    Science.gov (United States)

    Stramel, A. A.; Gupta, M. C.; Lee, H. R.; Yu, J.; Edwards, W. C.

    2010-12-01

    In this work, we report on the fabrication of carbon nanotube thin films via pulsed laser deposition using a pulsed, diode pumped, Tm:Ho:LuLF laser with 2 μm wavelength. The thin films were deposited on silicon substrates using pure carbon nanotube targets and polystyrene-carbon nanotube composite targets. Raman spectra, scanning electron micrographs, and transmission electron micrographs show that carbon nanotubes are present in the deposited thin films, and that the pulsed laser deposition process causes minimal degradation to the quality of the nanotubes when using pure carbon nanotube targets.

  4. Resonant infrared pulsed-laser deposition of a sorbent chemoselective polymer

    DEFF Research Database (Denmark)

    Bubb, D.M.; Horwitz, J.S.; McGill, R.A.

    2001-01-01

    Fluoropolyol, a sorbent chemoselective polymer, has been deposited as a thin film by resonant infrared pulsed laser deposition using a free electron laser operating at 2.90 mum, a wavelength resonant with the hydroxl stretch. A comparison of the infrared absorbance of the deposited film...

  5. Nanometer sized structures grown by pulsed laser deposition

    KAUST Repository

    ElZein, Basma

    2015-10-01

    Nanometer sized materials can be produced by exposing a target to a laser source to remove material from the target and deposit the removed material onto a surface of a substrate to grow a thin film in a vacuum chamber

  6. Polycrystalline ZnTe thin film on silicon synthesized by pulsed laser deposition and subsequent pulsed laser melting

    Science.gov (United States)

    Xu, Menglei; Gao, Kun; Wu, Jiada; Cai, Hua; Yuan, Ye; Prucnal, S.; Hübner, R.; Skorupa, W.; Helm, M.; Zhou, Shengqiang

    2016-03-01

    ZnTe thin films on Si substrates have been prepared by pulsed laser deposition and subsequent pulsed laser melting (PLM) treatment. The crystallization during PLM is confirmed by Raman scattering, x-ray diffraction and room temperature photoluminescence (PL) measurements. The PL results show a broad peak at 574 nm (2.16 eV), which can be assigned to the transitions from the conduction band to the acceptor level located at 0.145 eV above the valence band induced by zinc-vacancy ionization. Our work provides an applicable approach to low temperature preparation of crystalline ZnTe thin films.

  7. Chalcogenide compounds made by pulsed laser deposition at 355 and 248 nm

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt; Cazzaniga, Andrea Carlo; Crovetto, Andrea;

    Thin films made by pulsed laser deposition may differ depending on the laser wavelength. We compared ZnS, Cu2SnS3 and a target enriched with SnS relative to Cu2SnS3 using 355 nm and 248 nm lasers......Thin films made by pulsed laser deposition may differ depending on the laser wavelength. We compared ZnS, Cu2SnS3 and a target enriched with SnS relative to Cu2SnS3 using 355 nm and 248 nm lasers...

  8. Pulsed laser deposition of ZnSe N epilayers

    CERN Document Server

    Boo, B H; Xu, N

    2000-01-01

    A high-quality epitaxial film of nitrogen-doped ZsSe has been grown on a GaAs(100) substrate by using pulsed laser deposition assisted by an atomic nitrogen beam produced by a supersonic nozzle beam source. Atomic force microscopy shows that the surface of the ZnSe epilayer grown on GaAs(100) at 2 x 10 sup - sup 3 Torr is flat and dense. It also shows that its roughness is approx = 1.6 nm, less than that of epilayers grown by using metalorganic vapor phase epitaxy. X-ray diffraction results show that this ZnSe epilayer is a single crystalline epitaxial film. X-ray photoelectron spectroscopy (XPS) indicates that the epilayer is composed of 84 % Zn and Se, 10 % N, and 6 % O; other impurities are rare. The XPS spectra involving the Zn(2p sub 3 sub / sub 2) and the N(1s) core levels also indicate that the concentration of doped nitrogen atoms is above 10 sup 2 sup 1 /cm sup 3.

  9. Doped Titanium Dioxide Films Prepared by Pulsed Laser Deposition Method

    Directory of Open Access Journals (Sweden)

    Juguang Hu

    2012-01-01

    Full Text Available TiO2 was intensively researched especially for photocatalystic applications. The nitrogen-doped TiO2 films prepared by pulsed laser deposition (PLD method were reviewed, and some recent new experimental results were also presented in this paper. A new optical transmission method for evaluating the photocatalystic activity was presented. The main results are (1 PLD method is versatile for preparing oxide material or complex component films with excellent controllability and high reproducibility. (2 Anatase nitrogen-doped TiO2 films were prepared at room temperature, 200°C, and 400°C by PLD method using novel ceramic target of mixture of TiN and TiO2. UV/Vis spectra, AFM, Raman spectra, and photocatalystic activity for decomposition of methyl orange (MO tests showed that visible light response was improved at higher temperature. (3 The automatic, continuous optical transmission autorecorder method is suitable for detecting the photodecomposition dynamic process of organic compound.

  10. Influence of laser pulse frequency on the microstructure of aluminum nitride thin films synthesized by pulsed laser deposition

    Science.gov (United States)

    Antonova, K.; Duta, L.; Szekeres, A.; Stan, G. E.; Mihailescu, I. N.; Anastasescu, M.; Stroescu, H.; Gartner, M.

    2017-02-01

    Aluminum Nitride (AlN) thin films were synthesized on Si (100) wafers at 450 °C by pulsed laser deposition. A polycrystalline AlN target was multipulsed irradiated in a nitrogen ambient, at different laser pulse repetition rate. Grazing Incidence X-Ray Diffraction and Atomic Force Microscopy analyses evidenced nanocrystallites with a hexagonal lattice in the amorphous AlN matrix. The thickness and optical constants of the layers were determined by infrared spectroscopic ellipsometry. The optical properties were studied by Fourier Transform Infrared reflectance spectroscopy in polarised oblique incidence radiation. Berreman effect was observed around the longitudinal phonon modes of the crystalline AlN component. Angular dependence of the A1LO mode frequency was analysed and connected to the orientation of the particles' optical axis to the substrate surface normal. The role of the laser pulse frequency on the layers' properties is discussed on this basis.

  11. Matrix shaped pulsed laser deposition: New approach to large area and homogeneous deposition

    Energy Technology Data Exchange (ETDEWEB)

    Akkan, C.K.; May, A. [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany); Hammadeh, M. [Department for Obstetrics, Gynecology and Reproductive Medicine, IVF Laboratory, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Abdul-Khaliq, H. [Clinic for Pediatric Cardiology, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Aktas, O.C., E-mail: cenk.aktas@inm-gmbh.de [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany)

    2014-05-01

    Pulsed laser deposition (PLD) is one of the well-established physical vapor deposition methods used for synthesis of ultra-thin layers. Especially PLD is suitable for the preparation of thin films of complex alloys and ceramics where the conservation of the stoichiometry is critical. Beside several advantages of PLD, inhomogeneity in thickness limits use of PLD in some applications. There are several approaches such as rotation of the substrate or scanning of the laser beam over the target to achieve homogenous layers. On the other hand movement and transition create further complexity in process parameters. Here we present a new approach which we call Matrix Shaped PLD to control the thickness and homogeneity of deposited layers precisely. This new approach is based on shaping of the incoming laser beam by a microlens array and a Fourier lens. The beam is split into much smaller multi-beam array over the target and this leads to a homogenous plasma formation. The uniform intensity distribution over the target yields a very uniform deposit on the substrate. This approach is used to deposit carbide and oxide thin films for biomedical applications. As a case study coating of a stent which has a complex geometry is presented briefly.

  12. Surface electronic and structural properties of nanostructured titanium oxide grown by pulsed laser deposition

    NARCIS (Netherlands)

    Fusi, M.; Maccallini, E.; Caruso, T.; Casari, C. S.; Bassi, A. Li; Bottani, C. E.; Rudolf, P.; Prince, K. C.; Agostino, R. G.

    2011-01-01

    Titanium oxide nanostructured thin films synthesized by pulsed laser deposition (PLD) were here characterized with a multi-technique approach to investigate the relation between surface electronic, structural and morphological properties. Depending on the growth parameters, these films present chara

  13. Pulsed Laser Deposition of YBCO With Yttrium Oxide Buffer Layers (Postprint)

    Science.gov (United States)

    2012-02-01

    AFRL-RZ-WP-TP-2012-0092 PULSED LASER DEPOSITION OF YBCO WITH YTTRIUM OXIDE BUFFER LAYERS (POSTPRINT) Paul N. Barnes, Timothy J. Haugan...Paper Postprint 01 January 2002 – 01 January 2004 4. TITLE AND SUBTITLE PULSED LASER DEPOSITION OF YBCO WITH YTTRIUM OXIDE BUFFER LAYERS (POSTPRINT...Textured metallic substrate based HTS coated conductors with the YBCO /CeO2/YSZ/CeO2/Ni architecture have already been shown to exhibit high current

  14. Vitroceramic interface deposited on titanium substrate by pulsed laser deposition method.

    Science.gov (United States)

    Voicu, Georgeta; Miu, Dana; Dogaru, Ionut; Jinga, Sorin Ion; Busuioc, Cristina

    2016-08-30

    Pulsed laser deposition (PLD) method was used to obtain biovitroceramic thin film coatings on titanium substrates. The composition of the targets was selected from SiO2-CaO-P2O5-(CaF2) systems and the corresponding masses were prepared using the sol-gel method. The depositions were performed in oxygen atmosphere (100mTorr), while the substrates were heated at 400°C. The PLD deposited films were analysed through different experimental techniques: X-ray diffraction, scanning (SEM, EDX) and transmission (HRTEM, SAED) electron microscopy and infra-red spectroscopy coupled with optical microscopy. They were also biologically tested by in vitro cell culture and the contact angle was determined. The bioevaluation results indicate a high biocompatibilty of the obtained materials, demonstrating their potential use for biomedical applications.

  15. Applications of ultra-short pulsed laser ablation: thin films deposition and fs/ns dual-pulse laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Teghil, R; De Bonis, A; Galasso, A [Dipartimento di Chimica, Universita della Basilicata, Via N. Sauro 85, 85100 Potenza (Italy); Santagata, A; Albano, G; Villani, P; Spera, D; Parisi, G P [CNR-IMIP, Unita di Potenza, Via S. Loja, 85050 Tito Scalo (Italy)], E-mail: roberto.teghil@unibas.it

    2008-10-15

    In this paper, we report a survey of two of the large number of possible practical applications of the laser ablation performed by an ultra-short pulse laser, namely pulsed laser deposition (PLD) and fs/ns dual-pulse laser-induced breakdown spectroscopy (DP-LIBS). These applications differ from those using just longer pulsed lasers as a consequence of the distinctive characteristics of the plasma produced by ultra-short laser beams. The most important feature of this plasma is the large presence of particles with nanometric size which plays a fundamental role in both applications.

  16. Resonant Infrared Matrix Assisted Pulsed Laser Deposition of Polymers: Improving the Morphology of As-Deposited Films

    Science.gov (United States)

    Bubb, Daniel; Papantonakis, Michael; Collins, Brian; Brookes, Elijah; Wood, Joshua; Gurudas, Ullas

    2008-03-01

    Resonant infrared matrix assisted pulsed laser deposition has been used to deposit thin films of PMMA, a widely used industrial polymer. This technique is similar to conventional pulsed laser deposition, except that the polymer to be deposited is dissolved in a solvent and the solution is frozen before ablation in a vacuum chamber. The laser wavelength is absorbed by a vibrational band in the frozen matrix. The polymer lands on the substrate to form a film, while the solvent is pumped away. Our preliminary results show that the surface roughness of the as-deposited films depends strongly on the differential solubility radius, as defined by Hansen solubility parameters of the solvent and the solubility radius of the polymer. Our results will be compared with computational and experimental studies of the same polymer using a KrF (248 nm) laser. The ejection mechanism will be discussed as well as the implications of these results for the deposition of smooth high quality films.

  17. Pulsed laser deposition of graphite in air and in vacuum for field emission studies

    Energy Technology Data Exchange (ETDEWEB)

    Jadhav, Harshada; Singh, A.K.; Sinha, Sucharita, E-mail: ssinha@barc.gov.in

    2015-07-15

    A comparative study of pulsed laser deposition (PLD) based carbon films when deposited either, in atmospheric air, or under vacuum, has been performed. Micro-structural characterization of deposited films was carried out employing X-ray diffraction and Raman spectroscopic techniques. While, nanocrystalline graphite phase was observed in carbon films deposited in air, PLD films deposited under vacuum were largely amorphous in nature. Field emission (FE) properties of films deposited in air and under vacuum were investigated. Superior FE behavior characterized by a lower turn-on field (2.72 V/μm) and high field enhancement factor (∼2580) was observed for PLD films deposited in air. This improved field emission demonstrated by carbon films deposited via PLD in air can be attributed to presence of nanocrystalline graphite aggregates in such carbon films and local field enhancement near the sp{sup 2} sites. Our results therefore, establish PLD in air as a simple technique for deposition of carbon films having good field emission capability. - Highlights: • Pulsed laser deposition of graphite films, deposited in air and in vacuum. • Micro-structural, X-ray diffraction and micro-Raman spectroscopic characterization of deposited films. • Field emission properties of deposited films investigated. • Superior field emission behavior observed for films deposited in air than in vacuum. • Pulsed laser deposition in air leads to carbon films with excellent field emission capability.

  18. Characterization and Electrical Properties of TiO2 Thin Films Deposited by Pulsed Laser Deposition

    Science.gov (United States)

    Badar, Nurhanna; Kamarulzaman, Norlida

    2011-12-01

    Thin film technology is very important in today's high-tech industry. TiO2 is a high-k dielectric material. Problems with thin film deposition arise when the thickness of the thin layers approaches a few hundred nm to less than 100 nm. High quality thin films within these dimensions are difficult to obtain. Issues of adhesion, crystal mismatch, crystal orientation, surface roughness, densification, etc. are problems that need to be addressed if good quality thin films for devices are to be fabricated. These factors have a relation with the thin film technique used. As an example, spin coating technique may be a cheaper technique but may not result in dense and very smooth surfaces. Pulsed LASER deposition (PLD) is a relatively newer method used in thin film fabrication. The advantages of PLD are, capability of very thin films being deposited on different types of substrates (up to monolayers), control of crystal orientation, capability of depositing materials with complex stoichiometry and ease of methodology with high throughput. This has industrial implications as a good method for thin film preparation. This work involves the deposition of TiO2 thin films using different deposition parameters and chamber environments.

  19. In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

    KAUST Repository

    Avila-Avendano, Jesus

    2016-04-09

    In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

  20. Diamond-like carbon and ceramic materials as protective coatings grown by pulsed laser deposition

    OpenAIRE

    Perera Mercado, Yibran Argenis

    2004-01-01

    A rather large number of nitride, carbide, and oxide thin films are used as hard and wear-resistant coatings, for optical, corrosive, and refractory applications that are of crucial importance. Additional requirements place even more stringent conditions on the deposition processes. The properties of coatings deposited by pulsed laser deposition are determined by the deposition parameters, the composition of the PLD plasma and its ionization states, the substrate conditions, etc.. In this way...

  1. Structural and optical properties of tellurite thin film glasses deposited by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Munoz-Martin, D.; Fernandez-Navarro, J.M. [Laser Processing Group, Instituto de Optica (CSIC), Serrano 121, 28006 Madrid (Spain); Gonzalo, J., E-mail: j.gonzalo@io.cfmac.csic.es [Laser Processing Group, Instituto de Optica (CSIC), Serrano 121, 28006 Madrid (Spain); Jose, G.; Jha, A. [Institute for Materials Research, University of Leeds, Clarendon Road, Leeds LS2 9JT (United Kingdom); Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica (CSIC), Marie Curie s/n, 28049 Cantoblanco (Spain); Domingo, C. [Instituto de Estructura de la Materia (CSIC), Serrano 121, 28006 Madrid (Spain); Garcia-Lopez, J. [Centro Nacional de Aceleradores, P. Tecnologico ' Cartuja 93' , 41092 Sevilla (Spain)

    2011-10-31

    Tellurite (TeO{sub 2}-TiO{sub 2}-Nb{sub 2}O{sub 5}) thin film glasses have been produced by pulsed laser deposition at room temperature at laser energy densities in the range of 0.8-1.5 J/cm{sup 2} and oxygen pressures in the range of 3-11 Pa. The oxygen concentration in the films increases with laser energy density to reach values very close to that of the bulk glass at 1.5 J/cm{sup 2}, while films prepared at 1.5 J/cm{sup 2} and pressures above 5 Pa show oxygen concentration in excess of 10% comparing to the glass. X-ray photoelectron spectroscopy shows the presence of elementary Te in films deposited at O{sub 2} pressures {<=} 5 Pa that is not detected at higher pressures, while analysis of Raman spectra of the samples suggests a progressive substitution of TeO{sub 3} trigonal pyramids by TeO{sub 4} trigonal bipyramids in the films when increasing their oxygen content. Spectroscopic ellipsometry analysis combined with Cauchy and effective medium modeling demonstrates the influence of these compositional and structural modifications on the optical response of the films. Since the oxygen content determines their optical response through the structural modifications induced in the films, those can be effectively controlled by tuning the deposition conditions, and films having large n (2.08) and reduced k (< 10{sup -4}) at 1.5 {mu}m have been produced using the optimum deposition conditions.

  2. Noble metal nanoparticles deposited on self-assembled monolayers using Pulsed Laser Deposition show coulomb blockade at room temperature

    NARCIS (Netherlands)

    Speets, Emiel A.; Dordi, Barbara; Ravoo, Bart Jan; Oncel, Nuri; Hallbäck, Ann-Sofie; Zandvliet, Harold J.W.; Poelsema, Bene; Rijnders, Guus; Blank, Dave H.A.; Reinhoudt, David N.

    2005-01-01

    Nanometer-sized noble-metal clusters are fabricated on top of alkylthiolate self-assembled monolayers (SAMs) on annealed gold by pulsed laser deposition at elevated pressures. The size distribution of the clusters depends on the metal and on the pressure during the deposition. Scanning tunneling mic

  3. Three-dimensional defects in CdTe films obtained by pulsed laser deposition

    NARCIS (Netherlands)

    Sagan, P; Virt, IS; Zawislak, J; Rudyj, IO; Kuzma, M

    2004-01-01

    The quality of Cd chalcodenides epitaxial films can be enhanced seriously by applying a pulsed (electron beam or laser beam) method for ablation of targets. The structure of laser deposited CdTe layers was investigated by transmission high energy electron diffraction. This method is very useful for

  4. Growth and thermoelectric properties of FeSb2 films produced by pulsed laser deposition

    DEFF Research Database (Denmark)

    Sun, Ye; Canulescu, Stela; Sun, Peijie

    2011-01-01

    by ablating specifically prepared compound targets made of Fe and Sb powders in atomic ratio of 1:4. The thermoelectric transport properties of FeSb2 films were investigated. Pulsed laser deposition was demonstrated as a method for production of good-quality FeSb2 films.......Thermoelectric FeSb2 films were produced by pulsed laser deposition on silica substrates in a low-pressure Ar environment. The growth conditions for near phase-pure FeSb2 films were confirmed to be optimized at a substrate temperature of 425°C, an Ar pressure of 2 Pa, and deposition time of 3 h...

  5. Pulsed laser deposition of permanent magnetic Nd2Fe14B thin films

    NARCIS (Netherlands)

    Geurtsen, A.J.M.; Kools, J.C.S.; Wit, L.; Lodder, J.C.

    1996-01-01

    Pulsed Laser Deposition (PLD) is applied to deposit thin (thickness typically 100 nm) films of Nd2Fe14B. It is shown that films can be grown which have the desired composition and phase. Nd2Fe14B grows with the c-axis along the film normal on 110 Al2O3 single crystal substrates covered with a Ta lay

  6. In-situ monitoring during pulsed laser deposition using RHEED at high pressure

    NARCIS (Netherlands)

    Blank, David H.A.; Rijnders, Augustinus J.H.M.; Koster, Gertjan; Rogalla, Horst

    1998-01-01

    Reflection high energy electron diffraction (RHEED) is, due to its surface sensitivity, often used for the analysis and monitoring of thin film growth in ultra-high vacuum deposition systems. RHEED is usually applied in combination with pulsed laser deposition (PLD) by adjusting the background

  7. Pulsed laser deposition of Cu-Sn-S for thin film solar cells

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt; Crovetto, Andrea; Bosco, Edoardo

    Thin films of copper tin sulfide were deposited from a target of the stoichiometry Cu:Sn:S ~1:2:3 using pulsed laser deposition (PLD). Annealing with S powder resulted in films close to the desired Cu2SnS3 stoichiometry although the films remained Sn rich. Xray diffraction showed that the final...

  8. Pure and Sn-doped ZnO films produced by pulsed laser deposition

    DEFF Research Database (Denmark)

    Holmelund, E.; Schou, Jørgen; Tougaard, S.;

    2002-01-01

    A new technique, metronome doping, has been used for doping of films during pulsed laser deposition (PLD). This technique makes it possible to dope continuously during film growth with different concentrations of a dopant in one deposition sequence. Films of pure and doped ZnO have been produced...

  9. Pulsed laser deposition-induced reduction of SrTiO3 crystals

    NARCIS (Netherlands)

    Scullin, Matthew L.; Ravichandran, Jayakanth; Yu, Choongho; Huijben, Mark; Seidel, Jan; Majumdar, Arun; Ramesh, R.; Ramesh, R.

    2010-01-01

    We report a generic method for fast and efficient reduction of strontium titanate (SrTiO3, STO) single crystals by pulsed laser deposition (PLD) of thin-films. The reduction was largely independent of the thin-film material deposited on the crystals. It is shown that thermodynamic conditions (450 °C

  10. Evolution of energy deposition during glass cutting with pulsed femtosecond laser radiation

    Science.gov (United States)

    Kalupka, C.; Großmann, D.; Reininghaus, M.

    2017-05-01

    We report on investigations of the energy deposition in the volume of thin glass during an ablation cutting process with pulsed femtosecond laser radiation by time-resolved pump-probe shadowgraphy. For a single laser pulse, the temporal evolution of the transient electronic excitation of the glass volume is imaged up to 10 ps after initial excitation. For an increasing number of laser pulses, the spatial excitation of the glass volume significantly changes compared to single pulse irradiation. Sharp spikes are observed, which reduce the transmission of the illuminating probe pulse. This indicates local maxima of the absorption and, therefore, energy deposition of the pump pulse energy in the glass volume. Furthermore, for an increasing number of pulses, different shapes of the surface ablation crater are observed. To study the correlation between the shape of the surface ablation crater and the energy deposition in the glass volume, simulations of the spatial intensity distribution of the pump pulse are executed by means of linear beam propagation method. We show that the transient excitation spikes observed by pump-probe shadowgraphy can be explained by refraction and diffraction of the laser radiation at the surface ablation crater. Our results provide an experimental validation for the physical reason of an ablation stop for an ablation cutting process. Moreover, the simulations allow for the prediction of damage inside the glass volume.

  11. Direct patterning of complex oxides by pulsed laser deposition through stencils

    Energy Technology Data Exchange (ETDEWEB)

    Riele, Paul te; Janssens, Arjen; Rijnders, Guus; Blank, Dave H A [University of Twente, Inorganic Material Science, Faculty of Science and Technology MESA Institute for Nanotechnology, PO Box 217, 7500 AE Enschede (Netherlands)

    2007-04-15

    The possibilities to grow isolated structures of complex oxides by pulsed laser deposition through stencils were investigated. A stencil consisting of a SiN membrane with apertures of several hundred nanometers embedded in a Si chip is placed in front of a heated substrate (up to 750 degrees Celsius). Deposition through these apertures results in resistless, direct patterning by local deposition of complex oxides like ferroelectric Lead Zirconate Titanate. The created isolated structures were analyzed by AFM imaging. Under-deposition, in this work called broadening, is inevitable during stencil deposition and is depending on deposition parameters, especially pressure. Different causes of broadening are mapped and discussed.

  12. UV and RIR matrix assisted pulsed laser deposition of organic MEH-PPV films

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Papantonalis, M.R.; Auyeung, R.C.Y.

    2004-01-01

    were analyzed by Fourier transform infrared spectroscopy, UV-visible absorbance and photoluminescence. Photoluminescent material was deposited by RIR-MAPLE and 248-nm MAPLE, while the RIR-PLD and 193-nm-MAPLE depositions displayed the smoothest surfaces but did not show photoluminescence. (C) 2003......-PLD). For the first time resonant infrared matrix assisted pulsed laser evaporation (RIR-MAPLE) was successfully demonstrated on a luminescent polymer system. In addition to this, an excimer laser has been used for UV-MAPLE depositions at 193 and 248-nm irradiation. Films deposited onto NaCl and quartz substrates...

  13. Pulsed Laser Deposition of Er doped tellurite films on large area

    Energy Technology Data Exchange (ETDEWEB)

    Bouazaoui, M [Laboratoire PhLAM, UMR 8523, Groupe Photonique, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France); Capoen, B [Laboratoire PhLAM, UMR 8523, Groupe Photonique, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France); Caricato, A P [L3 group, Dipartimento di Fisica, Lecce, Via Arnesano, 73100 Lecce (Italy); Chiasera, A [CNR-IFN, CSMFO group, via Sommarive 14, 38100 Povo-Trento (Italy); Fazzi, A [L3 group, Dipartimento di Fisica, Lecce, Via Arnesano, 73100 Lecce (Italy); Ferrari, M [CNR-IFN, CSMFO group, via Sommarive 14, 38100 Povo-Trento (Italy); Leggieri, G [L3 group, Dipartimento di Fisica, Lecce, Via Arnesano, 73100 Lecce (Italy); Martino, M [L3 group, Dipartimento di Fisica, Lecce, Via Arnesano, 73100 Lecce (Italy); Mattarelli, M [Physics Department, CSMFO group, via Sommarive 14, 38100 Povo-Trento (Italy); Montagna, M [Physics Department, CSMFO group, via Sommarive 14, 38100 Povo-Trento (Italy); Romano, F [L3 group, Dipartimento di Fisica, Lecce, Via Arnesano, 73100 Lecce (Italy); Tunno, T [L3 group, Dipartimento di Fisica, Lecce, Via Arnesano, 73100 Lecce (Italy); Turrel, S [Universite des Sciences et Technologies de Lille, Laboratoire de Spectrochimie Infrarouge et Raman, LASIR - UMR 8516 du CNRS - Bat C5 - 59655 - Villeneuve d' Ascq cedex (France); Vishnubhatla, K [Physics Department, CSMFO group, via Sommarive 14, 38100 Povo-Trento (Italy)

    2007-04-15

    Thin films of Er{sup 3+}-doped tungsten tellurite glass have been prepared by the pulsed laser deposition technique using an ArF excimer laser. The depositions were performed at different O{sub 2} pressure (5, 10 Pa) and at different substrate temperatures (RT, 100deg. C and 200deg. C). The composition and the optical properties of the deposited films, such as transmission, dispersion curves of refraction index and extinction coefficient, and film thickness were studied for the different deposition parameters. Transparent films at the highest substrate temperature were obtained only for a higher oxygen pressure with respect to the RT conditions.

  14. Hyperthermal Pulsed-Laser Ablation Beams for Film Deposition and Surface Microstructural Engineering

    Energy Technology Data Exchange (ETDEWEB)

    Lowndes, D.H.

    1999-11-08

    This paper presents an overview of pulsed-laser ablation for film deposition and surface microstructure formation. By changing the ambient gas pressure from high vacuum to several Torr (several hundred Pa) and by selecting the pulsed-laser wavelength, the kinetic energy of ablated atoms/ions can be varied from several hundred eV down to {approximately}0.1 eV and films ranging from superhard to nanocrystalline may be deposited. Furthermore, cumulative (multi-pulse) irradiation of a semiconductor surface (e.g. silicon) in an oxidizing gas (0{sub 2}, SF{sub 6}) et atmospheric pressure can produce dense, self-organized arrays of high-aspect-ratio microcolumns or microcones. Thus, a wide range of materials synthesis and processing opportunities result from the hyperthermal flux and reactive growth conditions provided by pulsed-laser ablation.

  15. Characterization of ethylcellulose and hydroxypropyl methylcellulose thin films deposited by matrix-assisted pulsed laser evaporation

    Science.gov (United States)

    Palla-Papavlu, A.; Rusen, L.; Dinca, V.; Filipescu, M.; Lippert, T.; Dinescu, M.

    2014-05-01

    In this study is reported the deposition of hydroxypropyl methylcellulose (HPMC) and ethylcellulose (EC) by matrix-assisted pulsed laser evaporation (MAPLE). Both HPMC and EC were deposited on silicon substrates using a Nd:YAG laser (266 nm, 5 ns laser pulse and 10 Hz repetition rate) and then characterized by atomic force microscopy and Fourier transform infrared spectroscopy. It was found that for laser fluences up to 450 mJ/cm2 the structure of the deposited HPMC and EC polymer in the thin film resembles to the bulk. Morphological investigations reveal island features on the surface of the EC thin films, and pores onto the HPMC polymer films. The obtained results indicate that MAPLE may be an alternative technique for the fabrication of new systems with desired drug release profile.

  16. Characterization of ethylcellulose and hydroxypropyl methylcellulose thin films deposited by matrix-assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Palla-Papavlu, A., E-mail: apalla@nipne.ro [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania); Rusen, L.; Dinca, V.; Filipescu, M. [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania); Lippert, T. [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen PSI (Switzerland); Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, PO Box MG-36, Magurele, RO-077125 Bucharest (Romania)

    2014-05-01

    In this study is reported the deposition of hydroxypropyl methylcellulose (HPMC) and ethylcellulose (EC) by matrix-assisted pulsed laser evaporation (MAPLE). Both HPMC and EC were deposited on silicon substrates using a Nd:YAG laser (266 nm, 5 ns laser pulse and 10 Hz repetition rate) and then characterized by atomic force microscopy and Fourier transform infrared spectroscopy. It was found that for laser fluences up to 450 mJ/cm{sup 2} the structure of the deposited HPMC and EC polymer in the thin film resembles to the bulk. Morphological investigations reveal island features on the surface of the EC thin films, and pores onto the HPMC polymer films. The obtained results indicate that MAPLE may be an alternative technique for the fabrication of new systems with desired drug release profile.

  17. Biomolecular papain thin films grown by matrix assisted and conventional pulsed laser deposition: A comparative study

    Science.gov (United States)

    György, E.; Pérez del Pino, A.; Sauthier, G.; Figueras, A.

    2009-12-01

    Biomolecular papain thin films were grown both by matrix assisted pulsed laser evaporation (MAPLE) and conventional pulsed laser deposition (PLD) techniques with the aid of an UV KrF∗ (λ =248 nm, τFWHM≅20 ns) excimer laser source. For the MAPLE experiments the targets submitted to laser radiation consisted on frozen composites obtained by dissolving the biomaterial powder in distilled water at 10 wt % concentration. Conventional pressed biomaterial powder targets were used in the PLD experiments. The surface morphology of the obtained thin films was studied by atomic force microscopy and their structure and composition were investigated by Fourier transform infrared spectroscopy. The possible physical mechanisms implied in the ablation processes of the two techniques, under comparable experimental conditions were identified. The results showed that the growth mode, surface morphology as well as structure of the deposited biomaterial thin films are determined both by the incident laser fluence value as well as target preparation procedure.

  18. XPS analysis and luminescence properties of thin films deposited by the pulsed laser deposition technique

    Science.gov (United States)

    Dolo, J. J.; Swart, H. C.; Coetsee, E.; Terblans, J. J.; Ntwaeaborwa, O. M.; Dejene, B. F.

    2010-04-01

    This paper presents the effect of substrate temperature and oxygen partial pressure on the photoluminescence (PL) intensity of the Gd2O2S:Tb3 + thin films that were grown by using pulsed laser deposition (PLD). The PL intensity increased with an increase in the oxygen partial pressure and substrate temperature. The thin film deposited at an oxygen pressure of 900 mTorr and substrate temperature of 900°C was found to be the best in terms of the PL intensity of the Gd2O2S:Tb3 + emission. The main emission peak due to the 5D4-7F5 transition of Tb was measured at a wavelength of 545 nm. The stability of these thin films under prolonged electron bombardment was tested with a combination of techniques such as X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and Cathodoluminescence (CL) spectroscopy. It was shown that the main reason for the degradation in luminescence intensity under electron bombardment is the formation of a non-luminescent Gd2O3 layer, with small amounts of Gd2S3, on the surface.

  19. Thin films deposited by femtosecond pulsed laser ablation of tungsten carbide

    Science.gov (United States)

    De Bonis, A.; Teghil, R.; Santagata, A.; Galasso, A.; Rau, J. V.

    2012-09-01

    Ultra-short Pulsed Laser Deposition has been applied to the production of thin films from a tungsten carbide target. The gaseous phase obtained by the laser ablation shows a very weak primary plume, in contrast with a very strong secondary one. The deposited films, investigated by Scanning Electron Microscopy, Atomic Force Microscopy, X-Ray Photoelectron Spectroscopy and X-Ray Diffraction, present a mixture of WC and other phases with lower carbon content. All films are amorphous, independently from the substrate temperature. The characteristics of the deposits have been explained in terms of thermal evaporation and cooling rate of molten particles ejected from the target.

  20. Influence of dc bias on amorphous carbon deposited by pulse laser ablation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Amorphous carbon films were deposited on single-crystalline silicon and K9 glass by pulse laser ablation using different negative substrate bias. Scanning electron microscope (SEM) was used to observe morphology of the surface. Thickness and refractive index of the film deposited on K9 glass were measured by ellipsometry. Micro-hardness of films was measured relatively to single crystal silicon. All films deposited on silicon were analyzed by Raman spectra. All spectra were deconvoluted to three peaks. Line-width ratios varied similarly with bias voltage when the laser energy was kept invariant.

  1. Nanocomposite tantalum-carbon-based films deposited by femtosecond pulsed laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Benchikh, N. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France); Garrelie, F. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France); Wolski, K. [Ecole Nationale Superieure des Mines de Saint-Etienne, Centre SMS - URA CNRS 5146, 158 cours Fauriel, 42023 Saint-Etienne, Cedex 02 (France); Donnet, C. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France)]. E-mail: Christophe.Donnet@univ-st-etienne.fr; Fillit, R.Y. [Ecole Nationale Superieure des Mines de Saint-Etienne, Centre SMS - URA CNRS 5146, 158 cours Fauriel, 42023 Saint-Etienne, Cedex 02 (France); Rogemond, F. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France); Subtil, J.L. [Laboratoire Traitement du Signal et Instrumentation, UMR 5516, Universite J. Monnet, 10 rue Barrouin, 42000 Saint-Etienne (France); Rouzaud, J.N. [Laboratoire de Geologie de l' Ecole Normale Superieure de Paris 24, rue Lhomond 75231-Paris Cedex 5 (France); Laval, J.Y. [Laboratoire de Physique du Solide, UPR5 CNRS-ESPCI, 10 rue Vauquelin 75231-Paris Cedex 05 (France)

    2006-01-03

    Nanostructured coatings of metal (tantalum) containing diamond-like carbon (a-C:Ta) have been prepared by femtosecond pulsed laser deposition (PLD). The films, containing 15 at.% tantalum, have been deposited by ablating sequentially graphite and metallic tantalum in vacuum conditions with an amplified Ti:sapphire laser. The coatings have been investigated by X-ray photoelectron spectroscopy, grazing angle X-ray diffraction, energy filtered transmission electron microscopy, scanning and high resolution transmission electron microscopies. Evidence of metallic {alpha}-Ta and {beta}-Ta particles (diameter in the 100 nm range) and smaller quasi-amorphous tantalum clusters embedded in the carbonaceous matrix have been shown. A thin tantalum carbide interface between the carbon matrix and the top surface of the tantalum nodules has also been identified. The ability of femtosecond pulsed laser deposition to synthetize nanocomposite carbon-based films and to control their nanostructure is discussed.

  2. Ultra-thin Cu2ZnSnS4 solar cell by pulsed laser deposition

    DEFF Research Database (Denmark)

    Cazzaniga, Andrea Carlo; Crovetto, Andrea; Yan, Chang

    2017-01-01

    We report on the fabrication of a 5.2% efficiency Cu2ZnSnS4 (CZTS) solar cell made by pulsed laser deposition (PLD) featuring an ultra-thin absorber layer (less than 450 nm). Solutions to the issues of reproducibility and micro-particulate ejection often encountered with PLD are proposed. At the ......We report on the fabrication of a 5.2% efficiency Cu2ZnSnS4 (CZTS) solar cell made by pulsed laser deposition (PLD) featuring an ultra-thin absorber layer (less than 450 nm). Solutions to the issues of reproducibility and micro-particulate ejection often encountered with PLD are proposed....... At the optimal laser fluence, amorphous CZTS precursors with optimal stoichiometry for solar cells are deposited from a single target. Such precursors do not result in detectable segregation of secondary phases after the subsequent annealing step. In the analysis of the solar cell device, we focus on the effects...

  3. Formation of Metal Nano- and Micropatterns on Self-Assembled Monolayers by Pulsed Laser Deposition Through Nanostencils and Electroless Deposition

    NARCIS (Netherlands)

    Speets, Emiel A.; Riele, te Paul; Boogaart, van den Marc A.F.; Doeswijk, Lianne M.; Ravoo, Bart Jan; Rijnders, Guus; Brugger, Jürgen; Reinhoudt, David N.; Blank, Dave H.A.

    2006-01-01

    Patterns of noble-metal structures on top of self-assembled monolayers (SAMs) on Au and SiO2 substrates have been prepared following two approaches. The first approach consists of pulsed laser deposition (PLD) of Pt, Pd, Au, or Cu through nano- and microstencils. In the second approach, noble-metal

  4. Direct patterning of complex oxides by pulsed laser deposition through stencils

    NARCIS (Netherlands)

    Riele, te Paul; Janssens, Arjen; Rijnders, Guus; Blank, Dave H.A.

    2007-01-01

    The possibilities to grow isolated structures of complex oxides by pulsed laser deposition through stencils were investigated. A stencil consisting of a SiN membrane with apertures of several hundred nanometers embedded in a Si chip is placed in front of a heated substrate (up to 750 degrees Celsius

  5. Microstructural characterization of Co-based coating deposited by low power pulse laser cladding

    NARCIS (Netherlands)

    Farnia, A.; Ghaini, F. Malek; Ocelik, V.; De Hosson, J. Th. M.

    A detailed microstructural study of Stellite 6 coating deposited on a low carbon ferritic steel substrate using preplaced powder method and low power Nd:YAG pulse laser is performed. The grain structure and solidification texture of the coating are investigated by orientation imaging microscopy

  6. Epitaxial growth of atomically flat gadolinia-doped ceria thin films by pulsed laser deposition

    DEFF Research Database (Denmark)

    Chen, Yunzhong; Pryds, Nini; Schou, Jørgen;

    2011-01-01

    Epitaxial growth of Ce0.8Gd0.2O2(CGO) films on (001) TiO2-terminated SrTiO3 substrates by pulsed laser deposition was investigated using in situ reflective high energy electron diffraction. The initial film growth shows a Stransky–Krastanov growth mode. However, this three-dimensional island...

  7. Microstructural characterization of Co-based coating deposited by low power pulse laser cladding

    NARCIS (Netherlands)

    Farnia, A.; Ghaini, F. Malek; Ocelik, V.; De Hosson, J. Th. M.

    2013-01-01

    A detailed microstructural study of Stellite 6 coating deposited on a low carbon ferritic steel substrate using preplaced powder method and low power Nd:YAG pulse laser is performed. The grain structure and solidification texture of the coating are investigated by orientation imaging microscopy (OIM

  8. Nanostructured rhodium films for advanced mirrors produced by Pulsed Laser Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Uccello, A., E-mail: andrea.uccello@mail.polimi.it [Dipartimento di Energia, Politecnico di Milano, Milan (Italy); Dellasega, D., E-mail: david.dellasega@polimi.it [Dipartimento di Energia, Politecnico di Milano, Milan (Italy); Istituto di Fisica del Plasma, Consiglio Nazionale delle Ricerche, EURATOM-ENEA-CNR Association, Milan (Italy); Perissinotto, S., E-mail: stefano.perissinotto@iit.it [Center for Nano Science and Technology - Polimi, Istituto Italiano di Tecnologia, Milan (Italy); Lecis, N., E-mail: nora.lecis@polimi.it [Dipartimento di Meccanica, Politecnico di Milano, Milan (Italy); Passoni, M., E-mail: matteo.passoni@polimi.it [Dipartimento di Energia, Politecnico di Milano, Milan (Italy); Istituto di Fisica del Plasma, Consiglio Nazionale delle Ricerche, EURATOM-ENEA-CNR Association, Milan (Italy)

    2013-01-15

    In this paper advantages in the production by Pulsed Laser Deposition (PLD) of nanostructured, nanoengineered rhodium films to be used in tokamak First Mirrors (FMs) are shown. The peculiar PLD capability to tailor film structure at the nanoscale gives the possibility to deposit low roughness Rh films with a wide variety of structures and morphologies. By a proper movimentation of the substrate and using high fluence (10-19 J/cm{sup 2}) infrared laser pulses, it has been possible to deposit planar and homogeneous Rh films effectively suppressing surface defects on areas of the order of 10 cm{sup 2} with a satisfactory specular reflectivity. Multilayer deposition has been exploited to produce coatings with high adhesion and good mechanical properties. Finally, an estimation of the requirements to produce by PLD rhodium films suitable for the requests of ITER is provided.

  9. Radio-frequency oxygen-plasma-enhanced pulsed laser deposition of IGZO films

    Directory of Open Access Journals (Sweden)

    Chia-Man Chou

    2017-07-01

    Full Text Available We demonstrate the crystalline structures, optical transmittance, surface and cross-sectional morphologies, chemical compositions, and electrical properties of indium gallium zinc oxide (IGZO-based thin films deposited on glass and silicon substrates through pulsed laser deposition (PLD incorporated with radio-frequency (r.f.-generated oxygen plasma. The plasma-enhanced pulsed laser deposition (PEPLD-based IGZO thin films exhibited a c-axis-aligned crystalline (CAAC structure, which was attributed to the increase in Zn-O under high oxygen vapor pressure (150 mTorr. High oxygen vapor pressure (150 mTorr and low r.f. power (10 W are the optimal deposition conditions for fabricating IGZO thin films with improved electrical properties.

  10. Radio-frequency oxygen-plasma-enhanced pulsed laser deposition of IGZO films

    Science.gov (United States)

    Chou, Chia-Man; Lai, Chih-Chang; Chang, Chih-Wei; Wen, Kai-Shin; Hsiao, Vincent K. S.

    2017-07-01

    We demonstrate the crystalline structures, optical transmittance, surface and cross-sectional morphologies, chemical compositions, and electrical properties of indium gallium zinc oxide (IGZO)-based thin films deposited on glass and silicon substrates through pulsed laser deposition (PLD) incorporated with radio-frequency (r.f.)-generated oxygen plasma. The plasma-enhanced pulsed laser deposition (PEPLD)-based IGZO thin films exhibited a c-axis-aligned crystalline (CAAC) structure, which was attributed to the increase in Zn-O under high oxygen vapor pressure (150 mTorr). High oxygen vapor pressure (150 mTorr) and low r.f. power (10 W) are the optimal deposition conditions for fabricating IGZO thin films with improved electrical properties.

  11. Growth of arrays of Al-doped ZnO nanocones by pulsed laser deposition.

    Science.gov (United States)

    Sun, Ye; Addison, Katherine E; Ashfold, Michael N R

    2007-12-12

    Arrays of aligned Al-doped ZnO nanocones have been synthesized by pulsed laser deposition following excimer laser ablation of a ceramic ZnO target containing 2% Al(2)O(3) (by weight). The elemental composition, microstructural and optical properties of the products were examined by laser induced breakdown spectroscopy, electron microscopy, x-ray diffraction and room temperature photoluminescence measurements. The incident laser fluence was identified as a key parameter in nanocone formation. Their tapered morphologies and small tip diameters (approximately 5 nm) suggest that Al-doped ZnO nanocones could find application as field emitters and as a gas sensing material.

  12. Pulsed laser deposition of silicon dioxide thin films with silicone targets for fabricating waveguide devices

    Science.gov (United States)

    Okoshi, Masayuki; Kuramatsu, Masaaki; Inoue, Narumi

    2002-06-01

    Silicon dioxide (SiO2) thin films were deposited at room temperature by 193-nm ArF excimer laser ablation of silicone in oxygen atmosphere. Only the side chains of the target were photo-dissociated during ablation to deposit Si-O bonds on a substrate in high laser fluence at about 10 J/cm2. Oxygen gas worked to oxidize the Si-O bonds ejected from the target to from SiO2 thin films at the gas pressure of 4.4 X 10-2 Torr, in addition to reducing the isolated carbon mixed into the films. We also found that the deposited rate could control refractive index of the films. The refractive index of the film deposited at 0.05 nm/pulse is greater than that of the film at 0.1 nm/pulse. Thus, a 0.2-micrometers thick SiO2 cladding film deposited at 0.1 nm/pulse was firstly formed on the whole surface of a 100- micrometers -thick polyester film, and then a 0.6 micrometers -thick SiO2 core film at 0.05 nm/pulse was fabricated in a line on the sample. The sample functioned as a waveguide device for a 633-nm line of He-Ne laser.

  13. PULSED LASER DEPOSITION OF MAGNETIC MULTILAYERS FOR THE GRANT ENTITLED LASER PROCESSING OF ADVANCED MAGNETIC MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Monica Sorescu

    2003-10-11

    Nanostructured magnetite/T multilayers, with T = Ni, Co, Cr, have been prepared by pulsed laser deposition. The thickness of individual magnetite and metal layers takes values in the range of 5-40 nm with a total multilayer thickness of 100-120 nm. X-ray diffraction has been used to study the phase characteristics as a function of thermal treatment up to 550 C. Small amounts of maghemite and hematite were identified together with prevailing magnetite phase after treatments at different temperatures. The mean grain size of magnetite phase increases with temperature from 12 nm at room temperature to 54 nm at 550 C. The thermal behavior of magnetite in multilayers in comparison with powder magnetite is discussed. These findings were published in peer-reviewed conference proceedings after presentation at an international materials conference.

  14. Pulsed laser deposition growth of FeSb2 films for thermoelectric applications

    DEFF Research Database (Denmark)

    Sun, Ye; Canulescu, Stela; Sun, Peijie

    2011-01-01

    FeSb2 films were produced in a low-pressure Ar environment by pulsed laser deposition at 355 nm. The influence of growth parameters such as substrate temperature, Ar pressure and deposition time on the growth of FeSb2 films was studied. Nearly phase-pure FeSb2 films with thicknesses of 100–400 nm...... properties of FeSb2 films if they are to eventually reach thermoelectric applications at cryogenic temperatures....

  15. Pulsed Laser Deposition of BaTiO3 Thin Films on Different Substrates

    Directory of Open Access Journals (Sweden)

    Yaodong Yang

    2010-01-01

    Full Text Available We have studied the deposition of BaTiO3 (BTO thin films on various substrates. Three representative substrates were selected from different types of material systems: (i SrTiO3 single crystals as a typical oxide, (ii Si wafers as a semiconductor, and (iii Ni foils as a magnetostrictive metal. We have compared the ferroelectric properties of BTO thin films obtained by pulsed laser deposition on these diverse substrates.

  16. Characterisation of Pb thin films prepared by the nanosecond pulsed laser deposition technique for photocathode application

    OpenAIRE

    Lorusso, Antonella; Gontad, F.; Broitman, Esteban; Chiadroni, E.; Perrone, Walter

    2015-01-01

    Pb thin films were prepared by the nanosecond pulsed laser deposition technique on Si (100) and polycrystalline Nb substrates for photocathode application. As the photoemission performances of a cathode are strongly affected by its surface characteristics, the Pb films were grown at different substrate temperatures with the aim of modifying the morphology and structure of thin films. An evident morphological modification in the deposited films with the formation of spherical grains at higher ...

  17. Electrical and magnetic properties of ZnNiO thin films deposited by pulse laser deposition

    Institute of Scientific and Technical Information of China (English)

    Jie JIANG; Xue-tao WANG; Li-ping ZHU; Li-qiang ZHANG; Zhi-guo YANG; Zhi-zhen YE

    2011-01-01

    ZnNiO thin films with different contents of Ni (0-10 at.%) were fabricated on quartz and Si (100) substrates bY pulsed laser deposition (PLD).We measured the samples by X-ray diffraction (XRD),field-emission scanning electron microscope (FE-SEM),X-ray photoelectron spectroscopy (XPS),ultraviolet-visible spectrometer (UV-VIS),and Hall testing.When the Ni contents were below 3 at.%,partial Zn2+ ions were replaced by the Ni2+ ions without forming any other phases,which enhanced the conductivity of the film.When the Ni contents were above 3 at.%,Ni ions were at the interstitial sites,and Ni-related clusters and defects were able to emerge in the films,resulting in a worsening of electrical and optical properties.A ferromagnetic hysteresis with a coercive force of approximately 30 Oe was observed in the ZnNiO film with a Ni content of 3 at.% at room temperature.

  18. Photoluminescence Response in Carbon Films Deposited by Pulsed Laser Deposition onto GaAs Substrates at Low Vacuum

    Directory of Open Access Journals (Sweden)

    F. Caballero-Briones

    2016-01-01

    Full Text Available Carbon films were deposited onto GaAs substrates by pulsed laser deposition at low vacuum (10–15 mTorr from a graphite target. Films were prepared at different number of pulses (1500 to 6000 with fixed fluence (32 J/cm2, target-to-substrate distance, and pulse frequency using a Q:Switched Nd:YAG laser at 1064 nm operating at a frequency of 10 Hz and producing burst-mode pulses with total duration per shot of 49 ns. Films were characterized by optical microscopy, atomic force microscopy, laser induced breakdown spectroscopy, X-ray diffraction, and photoluminescence spectroscopy. Deposited films were visually smooth and adherent but on the other hand evidence of splashing was observed in all the films. Thickness varied linearly with the number of pulses from 8 to 42 μm with maximum height differences around 700 nm. Hexagonal and orthorhombic carbon was found in all the films and there was no evidence of nitrogen or oxygen incorporation during ablation process. Broad photoluminescence bands were observed and, particularly, emission peaks at 475–480 nm, 540–550 nm, 590 nm, and 625 nm. Bands tend to shift to lower wavelength with film thickness, suggesting that luminescence comes from splashed nanostructures influenced by the semiconducting substrate. This particular substrate effect is vanished as thickness of the films increases.

  19. Pulsed laser deposition of tin-doped indium oxide (ITO) on polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Yong, T.K. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Tou, T.Y. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)]. E-mail: tytou@mmu.edu.my; Teo, B.S. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)

    2005-07-30

    Indium tin oxide (ITO) films were deposited on polycarbonate (PC) substrates in oxygen at room temperature by pulsed laser deposition (PLD) using a Nd:YAG laser with 355 and 532 nm wavelengths. The ITO films were analyzed by the four-point probe technique, atomic force microscopy (AFM) and UV-visible-Near IR spectrophotometry for electrical conductivity, surface morphological and optical transmission properties, respectively. The main plume species were identified by using a fiber optic spectrometer, which showed that the emission intensity produced by the 355 nm laser wavelength was considerably stronger than that produced by the 532 nm laser wavelength. The ITO film resistivity was an order of magnitude higher than that achieved by a KrF excimer laser, but comparable to ITO-coated substrates prepared by the sputtering method.

  20. Morphology and structural studies of WO3 films deposited on SrTiO3 by pulsed laser deposition

    Science.gov (United States)

    Kalhori, Hossein; Porter, Stephen B.; Esmaeily, Amir Sajjad; Coey, Michael; Ranjbar, Mehdi; Salamati, Hadi

    2016-12-01

    WO3 films have been grown by pulsed laser deposition on SrTiO3 (001) substrates. The effects of substrate temperature, oxygen partial pressure and energy fluence of the laser beam on the physical properties of the films were studied. Reflection high-energy electron diffraction (RHEED) patterns during and after growth were used to determine the surface structure and morphology. The chemical composition and crystalline phases were obtained by XPS and XRD respectively. AFM results showed that the roughness and skewness of the films depend on the substrate temperature during deposition. Optimal conditions were determined for the growth of the highly oriented films.

  1. PbTe thin films grown by femtosecond pulsed laser deposition

    Science.gov (United States)

    Rodriguez, E.; Silva, D.; Moya, L.; Cesar, C. L.; Barbosa, L. C.; Schrank, A.; Souza Filho, C. R.; de Oliveira, E. P.

    2007-09-01

    PbTe thin films were grown on BK7 glass and Si(100) substrates using femtosecond pulsed laser deposition at room temperature. The influence of the background pressure and the laser fluence on the structural and optical characteristics of the PbTe films was studied. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the surface and structural properties of the deposited PbTe thin films, respectively. Transmission spectroscopy measurements in the visible and infrared region (VIS-IR) were used to investigate the optical properties of the PbTe thin films.

  2. Bismuth Oxide Thin Films Deposited on Silicon Through Pulsed Laser Ablation, for Infrared Detectors

    Science.gov (United States)

    Condurache-Bota, Simona; Constantinescu, Catalin; Tigau, Nicolae; Praisler, Mirela

    2016-12-01

    Infrared detectors are used in many human activities, from industry to military, telecommunications, environmental studies and even medicine. Bismuth oxide thin films have proved their potential for optoelectronic applications, but their uses as infrared sensors have not been thoroughly studied so far. In this paper, pulsed laser ablation of pure bismuth targets within a controlled oxygen atmosphere is proposed for the deposition of bismuth oxide films on Si (100) substrates. Crystalline films were obtained, whose uniformity depends on the deposition conditions (number of laser pulses and the use of a radio-frequency (RF) discharge of the oxygen inside the deposition chamber). The optical analysis proved that the refractive index of the films is higher than 3 and that their optical bandgap is around 1eV, recommending them for infrared applications.

  3. Pulsed laser deposition process of PLZT thin films using an infrared Nd:YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, T. [CCADET-UNAM, A.P. 70-186, Mexico D.F., C.P. 04510 (Mexico)]. E-mail: tupacgarcia@yahoo.com; Posada, E. de [IMRE-Physics Faculty, Havana University (Cuba); Bartolo-Perez, P. [CINVESTAV-IPN Unidad, Applied Physics Department, A.P. 73 Cordemex, Merida, Yuc. (Mexico); Programa de Corrosion del Golfo de Mexico, UAC, Compeche (Mexico); Pena, J.L. [CINVESTAV-IPN Unidad, Applied Physics Department, A.P. 73 Cordemex, Merida, Yuc. (Mexico); Diamant, R. [UAM-Unidad Iztapalapa, D.F. (Mexico); Calderon, F. [IMRE-Physics Faculty, Havana University (Cuba); Pelaiz, A. [IMRE-Physics Faculty, Havana University (Cuba)

    2006-03-15

    Pulsed laser depositions of PLZT thin films were performed using an Nd:YAG (1064 nm) laser. The growths took place in vacuum or in an oxygen background. Room temperature and 500 deg. C were the used substrate temperatures. The X-ray diffraction analysis revealed a preferential crystallographic orientation in the films grown at room temperature in vacuum. Such result is discussed. The velocity distribution functions of the species in the plasma plume were obtained from a time of flight study using optical emission spectroscopy. The maximums of these distributions functions fall around 10{sup 6} cm/s, equivalent to an energy range of 18-344 eV. Ionic species of heavy elements (like lead) achieved higher velocities than other lighter species. This result is linked to the creation of an accelerating spatial charge and to the thermal nature of the target material extraction that allows some elements to be released first than others. Chemical state variations of the elements present in the films were analyzed. Under these different growing conditions, lead chemical states varied the most.

  4. Comparison of the properties of Pb thin films deposited on Nb substrate using thermal evaporation and pulsed laser deposition techniques

    Energy Technology Data Exchange (ETDEWEB)

    Perrone, A., E-mail: alessio.perrone@unisalento.it [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); INFN-Istituto Nazionale di Fisica Nucleare e Università del Salento, 73100 Lecce (Italy); Gontad, F. [INFN-Istituto Nazionale di Fisica Nucleare e Università del Salento, 73100 Lecce (Italy); Lorusso, A.; Di Giulio, M. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Broitman, E. [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Ferrario, M. [Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, 00044 Frascati (Italy)

    2013-11-21

    Pb thin films were prepared at room temperature and in high vacuum by thermal evaporation and pulsed laser deposition techniques. Films deposited by both the techniques were investigated by scanning electron microscopy to determine their surface topology. The structure of the films was studied by X-ray diffraction in θ–2θ geometry. The photoelectron performances in terms of quantum efficiency were deduced by a high vacuum photodiode cell before and after laser cleaning procedures. Relatively high quantum efficiency (>10{sup −5}) was obtained for all the deposited films, comparable to that of corresponding bulk. Finally, film to substrate adhesion was also evaluated using the Daimler–Benz Rockwell-C adhesion test method. Weak and strong points of these two competitive techniques are illustrated and discussed. -- Highlights: •Comparison of Pb thin films deposited on Nb substrate by thermal evaporation and pulsed laser deposition (PLD). •Photoelectron performances of Pb thin films. •Good quality of adhesion strength of Pb films deposited by PLD.

  5. Pulsed laser deposition of AlMgB14 thin films

    Energy Technology Data Exchange (ETDEWEB)

    Britson, Jason Curtis [Iowa State Univ., Ames, IA (United States)

    2008-11-18

    Hard, wear-resistant coatings of thin film borides based on AlMgB14 have the potential to be applied industrially to improve the tool life of cutting tools and pump vanes and may account for several million dollars in savings as a result of reduced wear on these parts. Past work with this material has shown that it can have a hardness of up to 45GPa and be fabricated into thin films with a similar hardness using pulsed laser deposition. These films have already been shown to be promising for industrial applications. Cutting tools coated with AlMgB14 used to mill titanium alloys have been shown to substantially reduce the wear on the cutting tool and extend its cutting life. However, little research into the thin film fabrication process using pulsed laser deposition to make AlMgB14 has been conducted. In this work, research was conducted into methods to optimize the deposition parameters for the AlMgB14 films. Processing methods to eliminate large particles on the surface of the AlMgB14 films, produce films that were at least 1m thick, reduce the surface roughness of the films, and improve the adhesion of the thin films were investigated. Use of a femtosecond laser source rather than a nanosecond laser source was found to be effective in eliminating large particles considered detrimental to wear reduction properties from the films. Films produced with the femtosecond laser were also found to be deposited at a rate 100 times faster than those produced with the nanosecond laser. However, films produced with the femtosecond laser developed a relatively high RMS surface roughness around 55nm. Attempts to decrease the surface roughness were largely unsuccessful. Neither increasing the surface temperature of the substrate during deposition nor using a double pulse to ablate the material was found to be extremely successful to reduce the surface roughness. Finally, the adhesion of the thin films to M2 tool steel

  6. Functional porphyrin thin films deposited by matrix assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Cristescu, R., E-mail: rodica.cristescu@inflpr.ro [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, P.O. Box MG-36, Atomistilor 409, Bucharest-Magurele (Romania); Popescu, C.; Popescu, A.C.; Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, Lasers Department, P.O. Box MG-36, Atomistilor 409, Bucharest-Magurele (Romania); Ciucu, A.A. [Univeristy of Bucharest, Chemistry Department, Bucharest (Romania); Andronie, A.; Iordache, S.; Stamatin, I. [University of Bucharest, 3 Nano-SAE Research Center, P.O. Box MG-38, Bucharest-Magurele (Romania); Fagadar-Cosma, E. [Institute of Chemistry Timisoara of Romanian Academy, Department of Organic Chemistry, 300223 Timisoara (Romania); Chrisey, D.B. [Rensselaer Polytechnic Institute, School of Engineering, Department of Materials Science and Engineering, Troy 12180-3590, NY (United States)

    2010-05-25

    We report the first successful deposition of functionalized and nanostructured Zn(II)- and Co(II)-metalloporphyrin thin films by matrix assisted pulsed laser evaporation onto silicon wafers, quartz plates and screen-printed electrodes. The deposited nanostructures have been characterized by Raman spectrometry and cyclic voltammetry. The novelty of our contribution consists of the evaluation of the sensitivity of the MAPLE-deposited Zn(II)- and Co(II)-metalloporphyrin thin films on screen-printed carbon nanotube electrodes when challenged with dopamine.

  7. Investigations of ZnO thin films deposited by a reactive pulsed laser ablation

    Institute of Scientific and Technical Information of China (English)

    Y.; C.; SOO; H.; KANDEL; M.; A.; THOMAS; C.; P.; DAGHLIAN

    2009-01-01

    Highly transparent ZnO thin films were deposited at different substrate temperatures by pulsed laser deposition in an oxygen atmosphere. The thin films were characterized by various techniques including X-ray diffraction, scanning electron microscopy, optical absorption, and photoluminescence. We demonstrated that oriented wurtzite ZnO thin films could be deposited at room temperature using a high purity zinc target. Variable temperature photoluminescence revealed new characteristics in the band edge emission. The underlying mechanism for the observed phenomena was also discussed.

  8. Pulsed laser deposited Si on multilayer graphene as anode material for lithium ion batteries

    Directory of Open Access Journals (Sweden)

    Gouri Radhakrishnan

    2013-12-01

    Full Text Available Pulsed laser deposition and chemical vapor deposition were used to deposit very thin silicon on multilayer graphene (MLG on a nickel foam substrate for application as an anode material for lithium ion batteries. The as-grown material was directly fabricated into an anode without a binder, and tested in a half-cell configuration. Even under stressful voltage limits that accelerate degradation, the Si-MLG films displayed higher stability than Si-only electrodes. Post-cycling images of the anodes reveal the differences between the two material systems and emphasize the role of the graphene layers in improving adhesion and electrochemical stability of the Si.

  9. Growth Model for Pulsed-Laser Deposited Perovskite Oxide Films

    Institute of Scientific and Technical Information of China (English)

    WANG Xu; FEI Yi-Yan; ZHU Xiang-Dong; Lu Hui-Bin; YANG Guo-Zhen

    2008-01-01

    We present a multi-level growth model that yields some of the key features of perovskite oxide film growth as observed in the reflection high energy electron diffraction(RHEED)and ellipsometry studies.The model describes the effect of deposition,temperature,intra-layer transport,interlayer transport and Ostwald ripening on the morphology of a growth surface in terms of the distribution of terraces and step edges during and after deposition.The numerical results of the model coincide well with the experimental observation.

  10. Thin films of silver nanoparticles deposited in vacuum by pulsed laser ablation using a YAG:Nd laser

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, J.C., E-mail: alonso@servidor.unam.mx [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col Vicentina, Iztapalapa, 09340 Mexico, D.F. (Mexico); Diamant, R.; Castillo, P.; Acosta-Garcia, M.C.; Batina, N.; Haro-Poniatowski, E. [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col Vicentina, Iztapalapa, 09340 Mexico, D.F. (Mexico)

    2009-02-15

    We report the deposition of thin films of silver (Ag) nanoparticles by pulsed laser ablation in vacuum using the third line (355 nm) of a YAG:Nd laser. The nanostructure and/or morphology of the films was investigated as a function of the number of ablation pulses, by means of transmission electron microscopy and atomic force microscopy. Our results show that films deposited with a small number of ablation pulses (500 or less), are not continuous, but formed of isolated nearly spherical Ag nanoparticles with diameters in the range from 1 nm to 8 nm. The effect of increasing the number of pulses by one order of magnitude (5000) is to increase the mean diameter of the globular nanoparticles and also the Ag areal density. Further increase of the number of pulses, up to 10,000, produces the formation of larger and anisotropic nanoparticles, and for 15,000 pulses, quasi-percolated Ag films are obtained. The presence of Ag nanoparticles in the films was also evidenced from the appearance of a strong optical absorption band associated with surface plasmon resonance. This band was widened and its peak shifted from 425 nm to 700 nm as the number of laser pulses was increased from 500 to 15,000.

  11. Thin-film preparation by back-surface irradiation pulsed laser deposition using metal powder targets

    Science.gov (United States)

    Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Yamauchi, Makiko; Suda, Yoshiaki

    2017-01-01

    Several kinds of functional thin films were deposited using a new thin-film preparation method named the back-surface irradiation pulsed laser deposition (BIPLD) method. In this BIPLD method, powder targets were used as the film source placed on a transparent target holder, and then a visible-wavelength pulsed laser was irradiated from the holder side to the substrate. Using this new method, titanium oxide and boron nitride thin films were deposited on the silicon substrate. Surface scanning electron microscopy (SEM) images suggest that all of the thin films were deposited on the substrate with some large droplets irrespective of the kind of target used. The deposition rate of the films prepared by using this method was calculated from film thickness and deposition time to be much lower than that of the films prepared by conventional PLD. X-ray diffraction (XRD) measurement results suggest that rutile and anatase TiO2 crystal peaks were formed for the films prepared using the TiO2 rutile powder target. Crystal peaks of hexagonal boron nitride were observed for the films prepared using the boron nitride powder target. The crystallinity of the prepared films was changed by annealing after deposition.

  12. Characterisation of Pb thin films prepared by the nanosecond pulsed laser deposition technique for photocathode application

    Energy Technology Data Exchange (ETDEWEB)

    Lorusso, A., E-mail: antonella.lorusso@le.infn.it [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy); Gontad, F. [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy); Broitman, E. [Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping SE-581 83 (Sweden); Chiadroni, E. [Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, Frascati 00044 (Italy); Perrone, A. [Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, Università del Salento, Lecce 73100 (Italy)

    2015-03-31

    Pb thin films were prepared by the nanosecond pulsed laser deposition technique on Si (100) and polycrystalline Nb substrates for photocathode application. As the photoemission performances of a cathode are strongly affected by its surface characteristics, the Pb films were grown at different substrate temperatures with the aim of modifying the morphology and structure of thin films. An evident morphological modification in the deposited films with the formation of spherical grains at higher temperatures has been observed. X-ray diffraction measurements showed that a preferred orientation of Pb (111) normal to the substrate was achieved at 30 °C while the Pb (200) plane became strongly pronounced with the increase in the substrate temperature. Finally, a Pb thin film deposited on Nb substrate at 30 °C and tested as the photocathode showed interesting results for the application of such a device in superconducting radio frequency guns. - Highlights: • Pb thin films obtained by the nanosecond pulsed laser deposition technique at different substrate temperature. • The substrate temperature modifies the morphology and structure of Pb films. • Pb thin film was deposited at room temperature for photocathode application. • The Pb thin film photocathode was tested and the quantum efficiency of the device improved after laser cleaning treatment of the film surface.

  13. Pulsed laser deposition of antimicrobial silver coating on Ormocer (registered) microneedles

    Energy Technology Data Exchange (ETDEWEB)

    Gittard, S D; Narayan, R J; Jin, C; Monteiro-Riviere, N A [Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Ovsianikov, A; Chichkov, B N [Laser Zentrum Hannover, Hollerithallee 8, 30419 Hannover (Germany); Stafslien, S; Chisholm, B, E-mail: roger_narayan@msn.co [Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102 (United States)

    2009-12-15

    One promising option for transdermal delivery of protein- and nucleic acid-based pharmacologic agents involves the use of microneedles. However, microneedle-generated pores may allow microorganisms to penetrate the stratum corneum layer of the epidermis and cause local or systemic infection. In this study, microneedles with antimicrobial functionality were fabricated using two-photon polymerization-micromolding and pulsed laser deposition. The antibacterial activity of the silver-coated organically modified ceramic (Ormocer (registered) ) microneedles was demonstrated using an agar diffusion assay. Human epidermal keratinocyte viability on the Ormocer (registered) surfaces coated with silver was similar to that on uncoated Ormocer (registered) surfaces. This study indicates that coating microneedles with silver thin films using pulsed laser deposition is a useful and novel approach for creating microneedles with antimicrobial functionality. (communication)

  14. Characterization of Environmental Stability of Pulsed Laser Deposited Oxide Ceramic Coatings

    Energy Technology Data Exchange (ETDEWEB)

    ADAMS, THADM

    2004-03-02

    A systematic investigation of candidate hydrogen permeation materials applied to a substrate using Pulsed Laser Deposition has been performed. The investigation focused on application of leading permeation-resistant materials types (oxide, carbides, and metals) on a stainless steel substrate. and evaluation of the stability of the applied coatings. Type 304L stainless steel substrates were coated with aluminum oxide, chromium oxide, and aluminum. Characterization of the coating-substrate system adhesion was performed using scratch adhesion testing and microindentation. Coating stability and environmental susceptibility were evaluated for two conditions-air at 350 degrees Celsius and Ar-H2 at 350 degrees Celsius for up to 100 hours. Results from this study have shown the pulsed laser deposition process to be an extremely versatile technology that is capable of producing a sound coating/substrate system for a wide variety of coating materials.

  15. Surface modification of biomaterials by pulsed laser ablation deposition and plasma/gamma polymerization

    Science.gov (United States)

    Rau, Kaustubh R.

    Surface modification of stainless-steel was carried out by two different methods: pulsed laser ablation deposition (PLAD) and a combined plasma/gamma process. A potential application was the surface modification of endovascular stents, to enhance biocompatibility. The pulsed laser ablation deposition process, had not been previously reported for modifying stents and represented a unique and potentially important method for surface modification of biomaterials. Polydimethylsiloxane (PDMS) elatomer was studied using the PLAD technique. Cross- linked PDMS was deemed important because of its general use for biomedical implants and devices as well as in other fields. Furthermore, PDMS deposition using PLAD had not been previously studied and any information gained on its ablation characteristics could be important scientifically and technologically. The studies reported here showed that the deposited silicone film properties had a dependence on the laser energy density incident on the target. Smooth, hydrophobic, silicone-like films were deposited at low energy densities (100-150 mJ/cm2). At high energy densities (>200 mJ/cm2), the films had an higher oxygen content than PDMS, were hydrophilic and tended to show a more particulate morphology. It was also determined that (1)the deposited films were stable and extremely adherent to the substrate, (2)silicone deposition exhibited an `incubation effect' which led to the film properties changing with laser pulse number and (3)films deposited under high vacuum were similar to films deposited at low vacuum levels. The mechanical properties of the PLAD films were determined by nanomechanical measurements which are based on the Atomic Force Microscope (AFM). From these measurements, it was possible to determine the modulus of the films and also study their scratch resistance. Such measurement techniques represent a significant advance over current state-of-the-art thin film characterization methods. An empirical model for

  16. Structural and magnetic properties of Gd/Fe multilayers grown by pulsed laser deposition

    DEFF Research Database (Denmark)

    Kant, K. Mohan; Bahl, Christian Robert Haffenden; Pryds, Nini

    2010-01-01

    This work investigates the structural and the magnetic properties of Gd/Fe multilayered thin films grown by pulsed laser deposition onto Si (001) substrates at room temperature. he Fe layer thickness is varied from 70 to 150 nm and its effect on the structural and magnetic properties of Fe....../Gd/Fe sandwich multilayers has been explored. Gd films were found to change from amorphous to polycrystalline at a critical thickness of 20 nm....

  17. On the growth of gadolinia-doped ceria by pulsed laser deposition

    DEFF Research Database (Denmark)

    Pryds, Nini; Rodrigo, Katarzyna Agnieszka; Linderoth, Søren

    2009-01-01

    gadolinia doped ceria (GDC), an electrolytematerial, likely to replace the traditional yttria-stabilised zirconia (YSZ) for low temperature applications. GDC films were grown on a single crystal Si by pulsed laser deposition (PLD). The microstructure of the films as a function of growth time has been...... studied. We have found that the mean grain size increases with film thickness h as h2/5, in agreement with theoretical results....

  18. Pulsed laser deposition and in vitro characteristics of triphasic - HASi composition on titanium.

    Science.gov (United States)

    Palangadan, Rajesh; Sukumaran, Anil; Fernandez, Francis B; John, Annie; Varma, Harikrishna

    2014-02-01

    Pulsed laser deposition was used to deposit bioactive triphasic glass-ceramic composition (HASi) over titanium substrate using dense HASi target. Bioactive glass compositions are considered the most useful synthetic materials for immediate bone attachment because of its bioresorption, osteoconduction and osteointegration characteristics under in vivo conditions. The disadvantage of its brittleness associated with bioactive glass-ceramics has prompted its coating over metallic implants for the combination of duo mechanical and bioactive properties. The hard HASi target was able to undergo laser ablation under ambient gas pressure without bulk erosion of the target. Laser deposition was found to be efficient in depositing triphasic composition for immediate bone integration. The target and deposits were analyzed for the phase, composition and microstructural characteristics by means of X-ray diffraction, Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis and scanning electron microscopy. Simultaneously, the adherent nature and mechanical behaviour of deposits were confirmed by scratch test and micro-indentation methods. Further, the in vitro dissolution and bioactivity were assessed by soaking in simulated body fluid followed by elemental analysis using inductively coupled plasma spectroscopy. The deposits were found to be cell-friendly, which was indicated by the phenomenology of stem cells under in vitro conditions.

  19. Incorporation of gold into silicon by thin film deposition and pulsed laser melting

    Science.gov (United States)

    Warrender, Jeffrey M.; Hudspeth, Quentin; Malladi, Girish; Efstathiadis, Harry; Mathews, Jay

    2016-12-01

    We report on the incorporation of gold into silicon at a peak concentration of 1.9 × 1020 at./cm3, four orders of magnitude above the equilibrium solubility limit, using pulsed laser melting of a thin film deposited on the silicon surface. We vary the film thickness and laser process parameters (fluence, number of shots) to quantify the range of concentrations that can be achieved. Our approach achieves gold concentrations comparable to those achieved with ion implantation followed by pulsed laser melting, in a layer with high crystalline quality. This approach offers an attractive alternative to ion implantation for forming high quality, high concentration layers of transition metals like gold in silicon.

  20. Optical Characterization of SERS Substrates Based on Porous Au Films Prepared by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    V. V. Strelchuk

    2015-01-01

    Full Text Available The SERS (surface enhanced Raman spectroscopy substrates based on nanocomposite porous films with gold nanoparticles (Au NPs arrays were formed using the method of the pulsed laser deposition from the back low-energy flux of erosion torch particles on the glass substrate fixed at the target plain. The dependencies of porosity, and morphology of the surface of the film regions located near and far from the torch axis on the laser ablation regime, laser pulses energy density, their number, and argon pressure in the vacuum chamber, were ascertained. The Au NPs arrays with the controllable extinction spectra caused by the local surface plasmon resonance were prepared. The possibility of the formation of SERS substrates for the detection of the Rhodamine 6G molecules with the concentration 10−10 Mol/L with the enhancement factor 4·107 was shown.

  1. Fabrication of selective solar absorbers using pulsed laser deposition

    CSIR Research Space (South Africa)

    Yalisi, B

    2009-06-01

    Full Text Available , stainless steel to silicon 600 0.4 0.6 Po w er de n sit y (W /m 2 µ m ) Id ea l a bs o rb er re fle ct an ce Blackbody radiation 1000 1200 1400 1000 1200 1400 wafers. 200 400 0.2 Po w er de n sit y (W /m... and is called the Rayleigh range, the distance at which the laser beam has increased to twice the beam waist diameter and is the beam quality. is the wavelength of the KrF  R λ pi 2 2 M w z oR = ow 2M λ distance of the target from the lens...

  2. Pulsed laser deposition of barium metaplumbate thin films for ferroelectric capacitors

    Science.gov (United States)

    Mardare, A. I.; Mardare, C. C.; Fernandes, J. R. A.; Vilarinho, P. M.; Joanni, E.

    2003-08-01

    Barium metaplumbate thin films were deposited in situ by pulsed laser deposition on Si/SiO2/Ti/Pt substrates with a high deposition rate. The temperatures used ranged between 400 ^circ C and 700 ^circ C. As the deposition temperature was increased, the films assumed a strong (222) preferential orientation. This orientation of the electrodes was reflected on the PZT films, having a very big influence on their ferroelectric behavior. The PZT films made over BPO deposited at high temperature presented high values of remanent polarization (43 μC/cm^2) but indications of high leakage currents could be observed in the hysteresis loops. By using BPO bottom electrodes, a 30% improvement in the fatigue behavior of PZT capacitors when compared with the normal platinum electrodes was observed.

  3. High fluence deposition of polyethylene glycol films at 1064 nm by matrix assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Purice, Andreea; Schou, Jørgen; Kingshott, P.;

    2007-01-01

    Matrix assisted pulsed laser evaporation (MAPLE) has been applied for deposition of thin polyethylene glycol (PEG) films with infrared laser light at 1064 nm. We have irradiated frozen targets (of 1 wt.% PEG dissolved in water) and measured the deposition rate in situ with a quartz crystal 2...

  4. Target-plane deposition of diamond-like carbon in pulsed laser ablation of graphite

    Energy Technology Data Exchange (ETDEWEB)

    Yap, S.S. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Tou, T.Y. [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)], E-mail: tytou@mmu.edu.my

    2007-10-15

    In pulsed Nd:YAG laser ablation of highly oriented pyrolytic graphite (HOPG) at 10{sup -6} Torr, diamond-like carbon (DLC) are deposited at laser wavelengths of 1064, 532, and 355 nm on substrates placed in the target-plane. These target-plane samples are found to contain varying sp{sup 3} content and composed of nanostructures of 40-200 nm in size depending on the laser wavelength and laser fluence. The material and origin of sp{sup 3} in the target-plane samples is closely correlated to that in the laser-modified HOPG surface layer, and hardly from the backward deposition of ablated carbon plume. The surface morphology of the target-plane samples shows the columnar growth and with a tendency for agglomeration between nanograins, in particular for long laser wavelength at 1064 nm. It is also proposed that DLC formation mechanism at the laser-ablated HOPG is possibly via the laser-induced subsurface melting and resolidification.

  5. Comparison of the properties of Pb thin films deposited on Nb substrate using thermal evaporation and pulsed laser deposition techniques

    Science.gov (United States)

    Perrone, A.; Gontad, F.; Lorusso, A.; Di Giulio, M.; Broitman, E.; Ferrario, M.

    2013-11-01

    Pb thin films were prepared at room temperature and in high vacuum by thermal evaporation and pulsed laser deposition techniques. Films deposited by both the techniques were investigated by scanning electron microscopy to determine their surface topology. The structure of the films was studied by X-ray diffraction in θ-2θ geometry. The photoelectron performances in terms of quantum efficiency were deduced by a high vacuum photodiode cell before and after laser cleaning procedures. Relatively high quantum efficiency (>10-5) was obtained for all the deposited films, comparable to that of corresponding bulk. Finally, film to substrate adhesion was also evaluated using the Daimler-Benz Rockwell-C adhesion test method. Weak and strong points of these two competitive techniques are illustrated and discussed.

  6. Phase-selective vanadium dioxide (VO{sub 2}) nanostructured thin films by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Masina, B. N., E-mail: BMasina@csir.co.za, E-mail: slafane@cdta.dz [CSIR-National Laser Centre, PO BOX 395, Pretoria 0001 (South Africa); School of Physics, University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa); Lafane, S., E-mail: BMasina@csir.co.za, E-mail: slafane@cdta.dz; Abdelli-Messaci, S.; Kerdja, T. [Division des Milieux Ionisés et Laser, Centre de Développement des Technologies Avancées, Cité du 20 Août 1956, BP 17, Baba Hassen (Algeria); Wu, L. [CSIR-National Laser Centre, PO BOX 395, Pretoria 0001 (South Africa); Akande, A. A.; Mwakikunga, B. [DST/CSIR National Centre for Nano-Structured Materials, PO BOX 395, Pretoria 0001 (South Africa); Forbes, A. [School of Physics, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg (South Africa)

    2015-10-28

    Thin films of monoclinic nanostructured vanadium dioxide are notoriously difficult to produce in a selective manner. To date, post-annealing, after pulsed laser deposition (PLD), has been used to revert the crystal phase or to remove impurities, and non-glass substrates have been employed, thus reducing the efficacy of the transparency switching. Here, we overcome these limitations in PLD by optimizing a laser-ablation and deposition process through optical imaging of the laser-induced plasma. We report high quality monoclinic rutile-type vanadium dioxide (VO{sub 2}) (M1) nanoparticles without post-annealing, and on a glass substrate. Our samples demonstrate a reversible metal-to-insulator transition at ∼43 °C, without any doping, paving the way to switchable transparency in optical materials at room temperature.

  7. Investigation of droplet formation in pulsed Nd:YAG laser deposition of metals and silicon

    Energy Technology Data Exchange (ETDEWEB)

    Siew, Wee-Ong; Lee, Wai-Keat; Wong, Hin-Yong; Tou, Teck-Yong [Multimedia University, Faculty of Engineering, Cyberjaya, Selangor (Malaysia); Yong, Thian-Khok [Multimedia University, Faculty of Engineering, Cyberjaya, Selangor (Malaysia); Universiti Tunku Abdul Rahman, Faculty of Engineering and Science, Kuala Lumpur (Malaysia); Yap, Seong-Shan [Multimedia University, Faculty of Engineering, Cyberjaya, Selangor (Malaysia); Norwegian University of Science and Technology, Institute of Physics, Trondheim (Norway)

    2010-12-15

    In the process of pulsed laser deposition of nickel (Ni) and ruthenium (Ru) thin films, the occurrence of phase explosion in ablation was found to affect the deposition rate and enhance the optical emissions from the plasma plume. Faster thin-film growth rates coincide with the onset of phase explosion as a result of superheating and/or sub-surface boiling which also increased the particulates found on the thin-film surface. These particulates were predominantly droplets which may not be round but flattened and also debris for the case of silicon (Si) ablation. The droplets from Ni and Ru thin films were compared in terms of size distribution and number density for different laser fluences. The origins of these particulates were correlated to the bubble and ripple formations on the targets while the transfer to the thin film surface was attributed to the laser-induced ejection from the targets. (orig.)

  8. Growth parameter enhancement for MoS{sub 2} thin films synthesized by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Serna, Martha I.; Higgins, Marissa; Quevedo-Lopez, Manuel A. [Materials Science and Engineering Department, The University of Texas at Dallas, 800 W Campbell Road RL 10, Richardson TX 75080 (United States); Moreno, Salvador [Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080 (United States); Choi, Hyunjoo [Department of Advanced Materials Engineering, Kookmin University, Jeongneung-dong Seongbuk-gu, Seoul 136-702 (Korea, Republic of); Minary-Jolandan, Majid [Department of Mechanical Engineering, The University of Texas at Dallas, Richardson, TX 75080 (United States); Alan MacDiarmid Nanotech Institute, The University of Texas at Dallas, 800 W Campbell Road RL 10, Richardson TX 75080 (United States)

    2016-12-15

    Two-dimensional materials such as graphene and MoS{sub 2} have been the main focus of intense research efforts over the past few years. The most common method of exfoliating these materials, although efficient for lab-scale experiments, is not acceptable for large area and practical applications. Here, we report the deposition of MoS{sub 2} layered films on amorphous (SiO{sub 2}) and crystalline substrates (sapphire) using a pulsed laser deposition (PLD) method. Increased substrate temperature (∝700 C) and laser energy density (>530 mJ /cm{sup 2}) promotes crystalline MoS{sub 2} films < 20 nm, as demonstrated by fast Fourier transform (FFT) and transmission electron microscopy (TEM). The method reported here opens the possibility for large area layered MoS{sub 2} films by using a laser ablation processes. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Noble metal nanoparticles deposited on self-assembled monolayers by pulsed laser deposition show coulomb blockade at room temperature.

    Science.gov (United States)

    Speets, Emiel A; Dordi, Barbara; Ravoo, Bart Jan; Oncel, Nuri; Hallbäck, Ann-Sofie; Zandvliet, Harold J W; Poelsema, Bene; Rijnders, Guus; Blank, Dave H A; Reinhoudt, David N

    2005-04-01

    Nanometer-sized noble-metal clusters are fabricated on top of alkylthiolate self-assembled monolayers (SAMs) on annealed gold by pulsed laser deposition at elevated pressures. The size distribution of the clusters depends on the metal and on the pressure during the deposition. Scanning tunneling microscopy (STM) and conductive probe atomic force microscopy (CP-AFM) showed that the metal clusters are insulated from the substrate on top of the SAM. Coulomb blockades could be measured at room temperature by STM for palladium clusters on decanethiol SAMs.

  10. Nanostructured and amorphous-like tungsten films grown by pulsed laser deposition

    Science.gov (United States)

    Dellasega, D.; Merlo, G.; Conti, C.; Bottani, C. E.; Passoni, M.

    2012-10-01

    An experimental investigation of nanostructured, micrometer-thick, tungsten films deposited by pulsed laser deposition is presented. The films are compact and pore-free, with crystal grain sizes ranging from 14 nm to less than 2 nm. It is shown how, by properly tailoring deposition rate and kinetic energy of ablated species, it is possible to achieve a detailed and separate control of both film morphology and structure. The role of the main process parameters, He background pressure, laser fluence, and energy, is elucidated. In contrast with W films produced with other PVD techniques, β-phase growth is avoided and the presence of impurities and contaminants, like oxygen, is not correlated with film structure. These features make these films interesting for the development of coatings with improved properties, like increased corrosion resistance and enhanced diffusion barriers.

  11. Deposition of Y thin films by nanosecond UV pulsed laser ablation for photocathode application

    Energy Technology Data Exchange (ETDEWEB)

    Lorusso, A. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare-Lecce, 73100 Lecce (Italy); Anni, M. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Caricato, A.P. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare-Lecce, 73100 Lecce (Italy); Gontad, F., E-mail: francisco.gontad@le.infn.it [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare-Lecce, 73100 Lecce (Italy); Perulli, A. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Taurino, A. [National Research Council, Institute for Microelectronics & Microsystems, 73100 Lecce (Italy); Perrone, A. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Istituto Nazionale di Fisica Nucleare-Lecce, 73100 Lecce (Italy); Chiadroni, E. [Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, 00044 Frascati (Italy)

    2016-03-31

    In this work, yttrium (Y) thin films have been deposited on Si (100) substrates by the pulsed laser deposition technique. Ex-situ morphological, structural and optical characterisations of such films have been performed by scanning electron microscopy, X-ray diffractometry, atomic force microscopy and ellipsometry. Polycrystalline films with a thickness of 1.2 μm, homogenous with a root mean square roughness of about 2 nm, were obtained by optimised laser irradiation conditions. Despite the relatively high thickness, the films resulted very adherent to the substrates. The high quality of such thin films is important to the synthesis of metallic photocathodes based on Y thin film, which could be used as electron sources of high photoemission performance in radio-frequency guns. - Highlights: • Pulsed laser deposition of Yttrium thin films is investigated. • 1.2 μm thick films were deposited with very low RMS roughness. • The Y thin films were very adherent to the Si substrate • Optical characterisation showed a very high absorption coefficient for the films.

  12. In vivo evaluation of titanium implants coated with bioactive glass by pulsed laser deposition.

    Science.gov (United States)

    Borrajo, Jacinto P; Serra, Julia; González, Pío; León, Betty; Muñoz, Fernando M; López, M

    2007-12-01

    During the past years, different techniques, like chemical treatment, plasma spraying, sputtering, enamelling or sol-gel; and materials, like metals, hydroxylapatite, calcium phosphates, among others, have been applied in different combinations to improve the performance of prostheses. Among the techniques, Pulsed Laser Deposition (PLD) is very promising to produce coatings of bioactive glass on any metal alloy used as implant. In this work the biocompatibility of PLD coatings deposited on titanium substrates was examined by implantation in vivo. Different coating compositions were checked to find the most bioactive that was then applied on titanium and implanted into paravertebral muscle of rabbit.

  13. Quantitative TEM analysis of Al/Cu multilayer systems prepared by pulsed laser deposition

    DEFF Research Database (Denmark)

    Liu, Haihua; Pryds, Nini; Schou, Jørgen

    2010-01-01

    Thin films composed of alternating Al/Cu/Al layers were deposited on a (111) Si substrate using pulsed laser deposition (PLD). The thicknesses of the film and the individual layers, and the detailed internal structure within the layers were characterized by means of transmission electron microscopy...... for the formation of the first layer of nano-sized Al grains. The results demonstrate that the PLD technique is a powerful tool to produce nano-scale multilayered metal films with controllable thickness and grain sizes....

  14. Pulsed laser deposition of gadolinia doped ceria layers at moderate temperature – a seeding approach

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Heiroth, Sebastian; Pryds, Nini

    ), to the growth of dense, gas impermeable 10 mol% gadolinia-doped ceria (CGO10) solid electrolyte can be overcome by the seeding process. In order to evaluate the seed layer preparation, the effects of different thermal annealing treatments on the morphology, microstructure and surface roughness of ultrathin CGO...... the preparation of ultrathin seed layers in the first stage of the deposition process is often envisaged to control the growth and physical properties of the subsequent coating. This work suggests that the limitations of conventional pulsed laser deposition (PLD), performed at moderate temperature (400°C...

  15. Epitaxial growth of atomically flat gadolinia-doped ceria thin films by pulsed laser deposition

    DEFF Research Database (Denmark)

    Chen, Yunzhong; Pryds, Nini; Schou, Jørgen

    ), to the growth of dense, gas impermeable 10 mol% gadolinia-doped ceria (CGO10) solid electrolyte can be overcome by the seeding process. In order to evaluate the seed layer preparation, the effects of different thermal annealing treatments on the morphology, microstructure and surface roughness of ultrathin CGO...... the preparation of ultrathin seed layers in the first stage of the deposition process is often envisaged to control the growth and physical properties of the subsequent coating. This work suggests that the limitations of conventional pulsed laser deposition (PLD), performed at moderate temperature (400°C...

  16. Preparation and characterization of YBCO coating on metallic RABiT substrates by pulsed laser deposition

    Science.gov (United States)

    Gonal, M. R.; Prajapat, C. L.; Igalwar, P. S.; Maji, B. C.; Singh, M. R.; Krishnan, M.

    2016-05-01

    Superconducting YBCO films are coated on metallic Rolling Assisted Bi-axially Textured Substrates (RABiTS) Ni-5wt % W (NiW) (002) substrate using pulsed laser deposition (PLD) system. Targets of YBa2Cu3O7-δ (YBCO) and buffer layers of Ceria and 8 mole % Yttria Stabilized Zirconia (YSZ) of high density are synthesized. At each stage of deposition coatings are characterized by XRD. Transport studies show superconducting nature of YBCO only when two successive buffer layers of YSZ and CeO2 are used.

  17. Growth evolution of ZnO films deposited by pulsed laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, E.; Zaldo, C.; Vazquez, L. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, Madrid (Spain)]. E-mail: lvb@icmm.csic.es

    2001-07-16

    We study the surface morphology evolution of ZnO films grown by pulsed laser deposition. Atomic force microscopy measurements show the existence of two growth regimes. Initially, the growth morphology is determined by shadowing effects due to the angular spreading of the plume in the 0.1 mbar oxygen working pressure. For longer deposition times a stepped pyramid-like structure is developed, whose roughening and coarsening behaviours are in agreement with those expected for growth systems with step-edge barriers. (author). Letter-to-the-editor.

  18. Preparation and analysis of chemically gradient functional bioceramic coating formed by pulsed laser deposition.

    Science.gov (United States)

    Rajesh, P; Muraleedharan, C V; Sureshbabu, S; Komath, Manoj; Varma, Harikrishna

    2012-02-01

    Bioactive ceramic coatings based on calcium phosphates yield better functionality in the human body for a variety of metallic implant devices including orthopaedic and dental prostheses. In the present study chemically and hence functionally gradient bioceramic coating was obtained by pulsed laser deposition method. Calcium phosphate bioactive ceramic coatings based on hydroxyapatite (HA) and tricalcium phosphate (TCP) were deposited over titanium substrate to produce gradation in physico-chemical characteristics and in vitro dissolution behaviour. Sintered targets of HA and α-TCP were deposited in a multi target laser deposition system. The obtained deposits were characterized by X-ray diffraction, fourier transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray analysis. Inductively coupled plasma spectroscopy was used to estimate the in vitro dissolution behaviour of coatings. The variation in mechanical property of the gradient layer was evaluated through scratch test and micro-indentation hardness. The bioactivity was examined in vitro with respect to the ability of HA layer to form on the surface as a result of contact with simulated body fluid. It could be inferred that chemically gradient functional bioceramic coating can be produced by laser deposition of multiple sintered targets with variable chemical composition.

  19. Bioactive glass and hydroxyapatite thin films obtained by pulsed laser deposition

    Science.gov (United States)

    Gyorgy, E.; Grigorescu, S.; Socol, G.; Mihailescu, I. N.; Janackovic, D.; Dindune, A.; Kanepe, Z.; Palcevskis, E.; Zdrentu, E. L.; Petrescu, S. M.

    2007-07-01

    Bioactive glass (BG), calcium hydroxyapatite (HA), and ZrO 2 doped HA thin films were grown by pulsed laser deposition on Ti substrates. An UV KrF * ( λ = 248 nm, τ ≥ 7 ns) excimer laser was used for the multi-pulse irradiation of the targets. The substrates were kept at room temperature or heated during the film deposition at values within the (400-550 °C) range. The depositions were performed in oxygen and water vapor atmospheres, at pressure values in the range (5-40 Pa). The HA coatings were heat post-treated for 6 h in a flux of hot water vapors at the same temperature as applied during deposition. The surface morphology, chemical composition, and crystalline quality of the obtained thin films were studied by scanning electron microscopy, atomic force microscopy, and X-ray diffractometry. The films were seeded for in vitro tests with Hek293 (human embryonic kidney) cells that revealed a good adherence on the deposited layers. Biocompatibility tests showed that cell growth was better on HA than on BG thin films.

  20. Bioactive glass and hydroxyapatite thin films obtained by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gyorgy, E. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG 36, 77125 Bucharest (Romania) and Consejo Superior de Investigaciones Cientificas, Instituto de Ciencia de Materiales de Barcelona, Campus UAB, 08193 Bellaterra (Spain)]. E-mail: egyorgy@icmab.es; Grigorescu, S. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG 36, 77125 Bucharest (Romania); Socol, G. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG 36, 77125 Bucharest (Romania); Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, P.O. Box MG 36, 77125 Bucharest (Romania); Janackovic, D. [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade (Serbia); Dindune, A. [Institute of Inorganic Chemistry of the Riga Technical University (Latvia); Plasma and Ceramic Technologies Ltd. (PCT Ltd.) (Latvia); Kanepe, Z. [Institute of Inorganic Chemistry of the Riga Technical University (Latvia); Plasma and Ceramic Technologies Ltd. (PCT Ltd.) (Latvia); Palcevskis, E. [Plasma and Ceramic Technologies Ltd. (PCT Ltd.) (Latvia); Zdrentu, E.L. [Institute of Biochemistry, Splaiul Independentei 296, Bucharest (Romania); Petrescu, S.M. [Institute of Biochemistry, Splaiul Independentei 296, Bucharest (Romania)

    2007-07-31

    Bioactive glass (BG), calcium hydroxyapatite (HA), and ZrO{sub 2} doped HA thin films were grown by pulsed laser deposition on Ti substrates. An UV KrF{sup *} ({lambda} = 248 nm, {tau} {>=} 7 ns) excimer laser was used for the multi-pulse irradiation of the targets. The substrates were kept at room temperature or heated during the film deposition at values within the (400-550 deg. C) range. The depositions were performed in oxygen and water vapor atmospheres, at pressure values in the range (5-40 Pa). The HA coatings were heat post-treated for 6 h in a flux of hot water vapors at the same temperature as applied during deposition. The surface morphology, chemical composition, and crystalline quality of the obtained thin films were studied by scanning electron microscopy, atomic force microscopy, and X-ray diffractometry. The films were seeded for in vitro tests with Hek293 (human embryonic kidney) cells that revealed a good adherence on the deposited layers. Biocompatibility tests showed that cell growth was better on HA than on BG thin films.

  1. Electrochemical Response of Platinum Ultrathin Layer Formed by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Takeshi Ito

    2011-01-01

    Full Text Available Ultrathin layer of platinum (ULPt was deposited on glassy carbon (GC substrate by using pulsed laser deposition (PLD method, and electrochemical properties of the ULPt were discussed. The deposition was simply performed at room temperature with short deposition time. Atomic force microscopy and scanning electron microscopy images showed the flat surface of the ULPt. X-ray photoelectron spectroscopy (XPS characterized the ULPt in the Pt(0 state, and biding energy of ULPt was positively shifted. These results indicated that nanostructure of Pt thin layer was formed. The electrochemical activity of the prepared ULPt on GC substrate was superior to a bulk Pt electrode regarding the potential and the magnitude of current on oxidizing hydrogen peroxide. This fast and easily prepared low-cost electrode had the potential to replace a conventional bulk metal electrode.

  2. Optimizing coverage of metal oxide nanoparticle prepared by pulsed laser deposition on nonenzymatic glucose detection.

    Science.gov (United States)

    Kaneko, Satoru; Ito, Takeshi; Hirabayashi, Yasuo; Ozawa, Takeshi; Okuda, Tetsuya; Motoizumi, Yu; Hirai, Kiyohito; Naganuma, Yasuhiro; Soga, Masayasu; Yoshimoto, Mamoru; Suzuki, Koji

    2011-04-15

    Metal oxide nanoparticles prepared by pulsed laser deposition (PLD) were applied to nonenzymatic glucose detection. NiO nanoparticles with size of 3 nm were deposited on glassy carbon (GC) and silicon substrates at room temperature in an oxygen atmosphere. Transmission electron microscope (TEM) image showed nanoparticles with the size of 3 nm uniformly scattered on the Si(001) substrate. Unlike co-sputtering nanoparticle and carbon simultaneously, the PLD method can easily control the surface coverage of nanoparticles on the surface of substrate by deposition time. Cyclic voltammetry was performed on the samples deposited on the GC substrates for electrochemical detection of glucose. The differences between peak currents with and without glucose was used to optimize the coverage of nanoparticles on carbon electrode. The results indicated that optimal coverage of nanoparticles on carbon electrode.

  3. Nanostructured Diamond-Like Carbon Films Grown by Off-Axis Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Seong Shan Yap

    2015-01-01

    Full Text Available Nanostructured diamond-like carbon (DLC films instead of the ultrasmooth film were obtained by pulsed laser ablation of pyrolytic graphite. Deposition was performed at room temperature in vacuum with substrates placed at off-axis position. The configuration utilized high density plasma plume arriving at low effective angle for the formation of nanostructured DLC. Nanostructures with maximum size of 50 nm were deposited as compared to the ultrasmooth DLC films obtained in a conventional deposition. The Raman spectra of the films confirmed that the films were diamond-like/amorphous in nature. Although grown at an angle, ion energy of >35 eV was obtained at the off-axis position. This was proposed to be responsible for subplantation growth of sp3 hybridized carbon. The condensation of energetic clusters and oblique angle deposition correspondingly gave rise to the formation of nanostructured DLC in this study.

  4. Nanosecond pulsed laser deposition of TiO{sub 2}: nanostructure and morphology of deposits and plasma diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Mikel; Walczak, Malgorzata; Oujja, Mohamed; Cuesta, Angel [Instituto de Quimica Fisica Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Castillejo, Marta, E-mail: marta.castillejo@iqfr.csic.e [Instituto de Quimica Fisica Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)

    2009-10-30

    Nanostructured TiO{sub 2} films on Si (100) substrates have been grown by nanosecond pulsed laser deposition at the wavelengths of 266, 355 and 532 nm using a Q-switched Nd:YAG laser and TiO{sub 2} sintered rutile targets. The effect of laser irradiation wavelength, the temperature of the substrate and the presence of O{sub 2} as background gas on the crystallinity and surface structure of deposits were determined, together with the composition, expansion dynamics and thermodynamic parameters of the ablation plume. Deposits were analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, environmental scanning electron microscopy and atomic force microscopy, while in situ monitoring of the plume was carried out and characterized with spectral, temporal and spatial resolution by optical emission spectroscopy. Stoichiometric, crystalline deposits, with nanostructured morphology were obtained at substrate temperatures above 600 {sup o}C. Microscopic particulates were found overimposed on the nanostructured films but their size and density were significantly reduced by operating at short wavelength (266 nm) and upon addition of a low pressure of oxygen (0.05 Pa). The dominant crystalline phase is rutile at 355 and 532 nm. At the short irradiation wavelength, 266 nm, the preferred phase in the presence of oxygen is rutile, while anatase is preferably observed under vacuum. The narrowest size distribution and smallest nanoparticle diameters, of around 25 nm, were found by deposition at 266 nm under 0.05 Pa of oxygen.

  5. Random lasing of ZnO thin films grown by pulsed-laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Cachoncinlle, C., E-mail: christophe.cachoncinlle@univ-orleans.fr [GREMI, UMR 7344 CNRS—Université Orléans, 45067 Orléans Cedex 2 (France); Hebert, C.; Perrière, J. [Sorbonne Universités, UPMC Université Paris 06, UMR 7588, INSP, 75005 Paris (France); CNRS, UMR 7588, INSP, 75005 Paris (France); Nistor, M. [NILPRP, L 22 PO Box. MG-36, 77125 Bucharest—Magurele (Romania); Petit, A.; Millon, E. [GREMI, UMR 7344 CNRS—Université Orléans, 45067 Orléans Cedex 2 (France)

    2015-05-01

    Highlights: • Random lasing at RT in nanocrystalline ZnO PLD thin film (<100 nm). • Low optical pumping threshold (<30 kW cm{sup −2}) for UV random lasing. • Random lasing interpreted by the electron-hole plasma (EHP) model. - Abstract: Low-dimensional semiconductor structures on nanometer scale are of great interest because of their strong potential applications in nanotechnologies. We report here optical and structural properties on UV lasing in ZnO thin films. The ZnO films, 110 nm thick, were prepared using pulsed-laser deposition on c-cut sapphire substrates at 500 °C under 10{sup −2} oxygen pressure. The ZnO films are nearly stoichiometric, dense and display the wurtzite phase. The films are highly textured along the ZnO c-axis and are constituted of nanocrystallites. According to Hall measurements these films are conductive (0.11 Ω cm). Photoluminescence measurements reveals a so-called random lasing in the range 390 to 410 nm, when illuminating at 355 nm with a tripled frequency pulsed Nd-YAG laser. Such random lasing is obtained at rather low optical pumping, 45 kW cm{sup −2}, a value lower than those classically reported for pulsed-laser deposition thin films.

  6. KTN thin films prepared by pulsed laser deposition on transparent single crystal quartz (100)

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiaodong; PENG; Xiaofeng; ZHANG; Duanming

    2005-01-01

    Using the Sol-Gel method to produce the KTN ultrafine powder and the sintering technique with K2O atmosphere to prepare KTN ceramics as the targets instead of the KTN single crystal, highly oriented KTN thin films were produced on the transparent single crystal quartz (100) by the pulsed laser deposition (PLD). Since the thermal stress sustained by the quartz is relatively small, the limit temperature of the quartz substrates(300℃) is much lower than that of the P-Si substrates (560℃); the prepared thin film is at amorphous state. Increasing the pulsed laser energy density in the process incorporated with annealing the film after deposition at different temperatures converts the amorphous films into crystal. The optimal pulsed laser energy density and annealing temperature were 2.0 J/cm2 and 600℃, respectively. A discussion was made to understand the mechanism of film production at relatively low substrate temperature by PLD and effects of the annealing temperatures on the forming of the perovskite phase, and optimal conditions for the orientation of the crystal grain.

  7. Layered MoS{sub 2} grown on c-sapphire by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Yen-Teng; Ma, Chun-Hao; Luong, Tien-Tung; Wei, Lin-Lung; Yen, Tzu-Chun; Chu, Yung-Ching; Tu, Yung-Yi [Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu (China); Hsu, Wei-Ting; Chang, Wen-Hao [Department of Electrophysics, National Chiao Tung University, Hsinchu (China); Pande, Krishna Prasad [Department of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu (China); Chang, Edward Yi [Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu (China); Department of Electronics Engineering, National Chiao Tung University, Hsinchu (China)

    2015-03-01

    Layered growth of molybdenum disulphide (MoS{sub 2}) was successfully achieved by pulsed laser deposition (PLD) method on c -plane sapphire substrate. Growth of monolayer to a few monolayer MoS{sub 2}, dependent on the pulsed number of excimer laser in PLD is demonstrated, indicating the promising controllability of layer growth. Among the samples with various pulse number deposition, the frequency difference (A{sub 1g}-E{sup 1}{sub 2g}) in Raman analysis of the 70 pulse sample is estimated as 20.11 cm{sup -1}, suggesting a monolayer MoS{sub 2} was obtained. Two-dimensional (2D) layer growth of MoS{sub 2} is confirmed by the streaky reflection high energy electron diffraction (RHEED) patterns during growth and the cross-sectional view of transmission electron microscopy (TEM). The in-plane relationship, (0006) sapphire//(0002)MoS{sub 2} and [2 anti 1 anti 10] sapphire//[0 anti 1 anti 10]MoS{sub 2} is determined. The results imply that PLD is suitable for layered MoS{sub 2} growth. Additionally, the oxide states of Mo 3d core level spectra of PLD grown MoS{sub 2}, analysed by X-ray photoelectron spectroscopy (XPS), can be effectively reduced by adopting a post sulfurization process. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Fluence dependent electrical conductivity in aluminium thin films grown by infrared pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rebollar, Esther, E-mail: e.rebollar@csic.es [Instituto de Química Física Rocasolano, IQFR-CSIC, Serrano 19, 28006 Madrid (Spain); Martínez-Tong, Daniel E. [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain); Sanz, Mikel; Oujja, Mohamed; Marco, José F. [Instituto de Química Física Rocasolano, IQFR-CSIC, Serrano 19, 28006 Madrid (Spain); Ezquerra, Tiberio A. [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 121, 28006 Madrid (Spain); Castillejo, Marta [Instituto de Química Física Rocasolano, IQFR-CSIC, Serrano 19, 28006 Madrid (Spain)

    2016-11-30

    Highlights: • IR pulsed laser ablation of aluminium gives rise to smooth layers of several tens of nanometers. • Irradiation at fluences around 2.7 J/cm{sup 2} and above 7 J/cm{sup 2} resulted in deposition of amorphous aluminium oxide films and metallic aluminium films respectively. • Highly ionized species are more abundant in the ablation plumes generated at higher fluences. • It is possible to control by PLD the metal or dielectric character of the films. - Abstract: We studied the effect of laser fluence on the morphology, composition, structure and electric conductivity of deposits generated by pulsed laser ablation of a metallic aluminium target in vacuum using a Q-switched Nd:YAG laser (1064 nm, 15 ns). Upon irradiation for one hour at a repetition rate of 10 Hz, a smooth layer of several tens of nanometres, as revealed by atomic force microscopy (AFM) was deposited on glass. Surface chemical composition was determined by X-ray photoelectron spectroscopy, and to study the conductivity of deposits both I–V curves and conductive-AFM measurements were performed. Irradiation at fluences around 2.7 J/cm{sup 2} resulted in deposition of amorphous aluminium oxide films. Differently, at higher fluences above 7 J/cm{sup 2}, the films are constituted by metallic aluminium. Optical emission spectroscopy revealed that highly ionized species are more abundant in the ablation plumes generated at higher fluences. The results demonstrate the possibility to control by PLD the metal or dielectric character of the films.

  9. Optical Properties Dependence with Gas Pressure in AlN Films Deposited by Pulsed Laser Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J A; Riascos, H [Departamento de Fisica, Universidad Tecnologica de Pereira, Grupo plasma Laser y Aplicaciones A.A 097 (Colombia); Caicedo, J C [Grupo pelIculas delgadas, Universidad del Valle, Cali (Colombia); Cabrera, G; Yate, L, E-mail: jcaicedoangulo@gmail.com [Department de Fisica Aplicada i Optica, Universitat de Barcelona, Catalunya (Spain)

    2011-01-01

    AlN films were deposited by pulsed laser deposition technique (PLD) using an Nd: YAG laser ({lambda} = 1064 nm). The films were deposited in a nitrogen atmosphere as working gas; the target was an aluminum high purity (99.99%). The films were deposited with a laser fluence of 7 J/cm2 for 10 minutes on silicon (100) substrates. The substrate temperature was 300 deg. C and the working pressure was varied from 3 mtorr to 11 mtorr. The thickness measured by profilometer was 150 nm for all films. The crystallinity was observed via XRD pattern, the morphology and composition of the films were studied using scanning electron microscopy (SEM) and Energy Dispersive X-ray analysis (EDX), respectively. The optical reflectance spectra and color coordinates of the films were obtained by optical spectral reflectometry technique in the range of 400 cm-1- 900 cm-1 by an Ocean Optics 2000 spectrophotometer. In this work, a clear dependence of the reflectance, dominant wavelength and color purity was found in terms of the applied pressure to the AlN films. A reduction in reflectance of about 55% when the pressure was increased from 3 mtorr to 11 mtorr was observed. This paper deals with the formation of AlN thin films as promising materials for the integration of SAW devices on Si substrates due to their good piezoelectric properties and the possibility of deposition at low temperature compatible with the manufacturing of Si integrated circuits.

  10. Atomic force microscopic characterization of films grown by inverse pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Egerhazi, L. [Department of Optics and Quantum Electronics, University of Szeged, P.O. Box 406, H-6701 Szeged (Hungary); Geretovszky, Zs. [Department of Optics and Quantum Electronics, University of Szeged, P.O. Box 406, H-6701 Szeged (Hungary); Csako, T. [Department of Optics and Quantum Electronics, University of Szeged, P.O. Box 406, H-6701 Szeged (Hungary); Szoerenyi, T. [Research Group on Laser Physics of the Hungarian Academy of Sciences, University of Szeged, P.O. Box 406, H-6701 Szeged (Hungary)]. E-mail: t.szorenyi@physx.u-szeged.hu

    2006-04-30

    Carbon nitride films have been deposited by KrF excimer laser ablation of a rotating graphite target in 5 Pa nitrogen ambient in an inverse pulsed laser deposition configuration, where the backward motion of the ablated species is utilised for film growth on substrates lying in the target plane. Topometric AFM scans of the films, exhibiting elliptical thickness distribution, have been recorded along the axes of symmetry of the deposition area. High resolution AFM scans revealed the existence of disk-like, or somewhat elongated rice-like features of 5-10 nm average thickness and {approx}100 nm largest dimension, densely packed over the whole, approximately 14 x 10 cm{sup 2} deposition area. The RMS roughness of the film decreased from 9 nm near to the laser spot down to 2 nm in the outer regions. Even the highest RMS value obtained for IPLD films was less than half of the typical, 25 nm roughness measured on simultaneously deposited PLD films.

  11. Pulsed-laser deposition of vicinal and c-axis oriented high temperature superconducting thin films

    CERN Document Server

    Rössler, R

    2000-01-01

    respect to the temperature, oxygen pressure and laser fluence. (Re,Hg)Ba sub 2 Ca sub ( n-1)Cu sub n O sub x films are synthesized on (001) and vicinal SrTiO sub 3 substrates in a two step process employing pulsed-laser deposition of Hg-free precursor films and Hg-vapour annealing in a sealed quartz tube. The sealed quartz tube technique is described in detail and the thermodynamics and the phase formation are discussed. The influence of the Hg-vapour pressure and the annealing temperature on the film properties are investigated. The influence of Hg-vapour annealing on Bi sub 2 Sr sub 2 CaCu sub 2 O sub x films is described. YBa sub 2 Cu sub 3 O sub x films with thicknesses 20 to 480 nm are deposited on vicinal SrTiO sub 3 substrates (10 degrees tilt angle). Variation of the resistivities and changes in the film morphology depending on film thickness are described. The influence of post-annealing treatments on the film properties is discussed. Pulsed-laser deposition (PLD) of high temperature superconducting ...

  12. Microstructural characterization and chemical compatibility of pulsed laser deposited yttria coatings on high density graphite

    Energy Technology Data Exchange (ETDEWEB)

    Sure, Jagadeesh [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Mishra, Maneesha [Physical Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102 (India); Tarini, M. [SRM University, Kattankulathur-603 203 (India); Shankar, A. Ravi; Krishna, Nanda Gopala [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Kuppusami, P. [Physical Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102 (India); Mallika, C. [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India); Mudali, U. Kamachi, E-mail: kamachi@igcar.gov.in [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam — 603 102 (India)

    2013-10-01

    Yttria coatings were deposited on high density (HD) graphite substrate by pulsed laser deposition method and subsequently annealing in vacuum at 1373 K was carried out to evaluate the thermal stability of the coatings. Yttria deposited on HD graphite samples were exposed to molten LiCl–KCl salt at 873 K for 3 h to evaluate the corrosion behavior of the coating for the purpose of pyrochemical reprocessing applications. The microstructure and the corrosion behavior of the yttria coating deposited on HD graphite in molten LiCl–KCl salt were evaluated by several characterization techniques. X-ray diffraction and Laser Raman patterns confirmed the presence of cubic phase of yttria in the coating. The surface morphology of yttria coating on HD graphite examined by scanning electron microscope and atomic force microscopy revealed the agglomeration of oxide particles and formation of clusters. After annealing at 1373 K, no appreciable grain growth of yttria particles could be observed. X-ray photoelectron spectroscopy analysis was carried out for elemental analysis before and after chemical compatibility test of the coated samples in molten LiCl–KCl salt to identify the corrosive elements present on the yttria coatings. The chemical compatibility and thermal stability of the yttria coating on HD graphite in molten LiCl–KCl salt medium have been established. - Highlights: • Y{sub 2}O{sub 3} coating was deposited on graphite by pulsed laser deposition method. • Chemical compatibility of Y{sub 2}O{sub 3} coating in LiCl–KCl salt at 873 K was studied. • Gibbs free energy change was positive for Y{sub 2}O{sub 3} reaction with Cl{sub 2}, U and UCl{sub 3}. • Y{sub 2}O{sub 3} coating exhibited better corrosion performance in molten LiCl–KCl salt.

  13. Thermochromic VO{sub 2} on Zinnwaldite Mica by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mathevula, L., E-mail: langu@tlabs.ac.za [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Western Cape (South Africa); Ngom, B.D.; Kotsedi, L.; Sechogela, P. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Western Cape (South Africa); Doyle, T.B. [Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Western Cape (South Africa); School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001 (South Africa); Ghouti, M.; Maaza, M. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Western Cape (South Africa)

    2014-09-30

    Highlights: • Vanadium dioxide was successfully synthesized by pulsed laser deposition method on mica. • The morphology evolution within the samples is characterized by a change from isolated and less-percolating (0 1 1) VO{sub 2} crystallites to a percolating granular configuration. • Without any post annealing, the films exhibit a textured nature with a VO{sub 2} (0 1 1) preferred crystallographic orientation and an elevated thermal variation of the electric resistance ratio R{sub S}/R{sub M} through the SMT at T ≈ 68 °C of the order of 10{sup 4} and a narrow ∼7 °C hysteresis. - Abstract: VO{sub 2} thin films have been deposited by pulsed laser deposition on Zinnwaldite Mica substrates. The crystal structure, chemical composition, morphology were determined and the semiconductor/metal transition (SMT) properties of the deposited films were investigated. Without any post annealing, the films exhibit a textured nature with a VO{sub 2} (0 1 1) preferred crystallographic orientation and an elevated thermal variation of the electric resistance ratio R{sub S}/R{sub M} through the SMT at T ≈ 68 °C of the order of 10{sup 4} and a narrow ∼7 °C hysteresis. In addition, the growth of the VO{sub 2} crystallites seem to be governed likely by a Volmer-Weber or Stranski-Krastanov mechanisms and certainly not a Frank-van Der Merwe process.

  14. Optical Properties of Nitrogen-Substituted Strontium Titanate Thin Films Prepared by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Alexander Wokaun

    2009-09-01

    Full Text Available Perovskite-type N-substituted SrTiO3 thin films with a preferential (001 orientation were grown by pulsed laser deposition on (001-oriented MgO and LaAlO3 substrates. Application of N2 or ammonia using a synchronized reactive gas pulse produces SrTiO3-x:Nx films with a nitrogen content of up to 4.1 at.% if prepared with the NH3 gas pulse at a substrate temperature of 720 °C. Incorporating nitrogen in SrTiO3 results in an optical absorption at 370-460 nm associated with localized N(2p orbitals. The estimated energy of these levels is ≈2.7 eV below the conduction band. In addition, the optical absorption increases gradually with increasing nitrogen content.

  15. Substrate dependent structural and magnetic properties of pulsed laser deposited Fe3O4 thin films.

    Science.gov (United States)

    Goyal, Rajendra N; Kaur, Davinder; Pandey, Ashish K

    2010-12-01

    Nanocrystalline iron oxide thin films have been deposited on various substrates such as quartz, MgO(100), and Si(100) by pulsed laser deposition technique using excimer KrF laser (248 nm). The orientations, crystallite size and lattice parameters were studied using X-ray diffraction. The XRD results show that the films deposited on MgO and Si substrates are highly oriented and show only (400) and (311) reflections respectively. On the other hand, the orientation of the films deposited on quarts substrate changed from (311) to (400) with an increase in the substrate temperature from 400 degrees C to 600 degrees C, indicating thereby that the film growth direction is highly affected with nature of substrate and substrate temperature. The surface morphology of the deposited films was studied using Atomic Force Microscopy (AFM) and spherical ball like regular features of nanometer size grains were obtained. The magnetic properties were studied by Superconducting Quantum Interference Device (SQUID) magnetometer in the magnetic field +/- 6 Tesla. The magnetic field dependent magnetization (M-H) curves of all the Fe3O4 thin films measured at 5 K and 300 K show the ferrimagnetic nature. The electrochemical sensing of dopamine studied for these films shows that the film deposited on MgO substrate can be used as a sensing electrode.

  16. Ultrashort Pulsed Laser Ablation of Magnesium Diboride: Plasma Characterization and Thin Films Deposition

    Directory of Open Access Journals (Sweden)

    Angela De Bonis

    2015-01-01

    Full Text Available A MgB2 target has been ablated by Nd:glass laser with a pulse duration of 250 fs. The plasma produced by the laser-target interaction, showing two temporal separated emissions, has been characterized by time and space resolved optical emission spectroscopy and ICCD fast imaging. The films, deposited on silicon substrates and formed by the coalescence of particles with nanometric size, have been analyzed by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, micro-Raman spectroscopy, and X-ray diffraction. The first steps of the films growth have been studied by Transmission Electron Microscopy. The films deposition has been studied by varying the substrate temperature from 25 to 500°C and the best results have been obtained at room temperature.

  17. Study of structural and optical properties of ZnO films grown by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lemlikchi, S., E-mail: lemlikchi_safo@yahoo.fr [Advanced Technology Development Centre, Cite 20 Aout 1956 BP 17 Baba Hassen, Algiers (Algeria); Abdelli-Messaci, S.; Lafane, S.; Kerdja, T. [Advanced Technology Development Centre, Cite 20 Aout 1956 BP 17 Baba Hassen, Algiers (Algeria); Guittoum, A.; Saad, M. [Nuclear Research Centre of Algiers, 2 Bd Frantz-Fanon, Algiers (Algeria)

    2010-07-01

    Wurtzite zinc oxides films (ZnO) were deposited on silicon (0 0 1) and corning glass substrates using the pulsed laser deposition technique. The laser fluence, target-substrate distance, substrate temperature of 300 deg. C were fixed while varying oxygen pressures from 2 to 500 Pa were used. It is observed that the structural properties of ZnO films depend strongly on the oxygen pressure and the substrate nature. The film crystallinity improves with decreasing oxygen pressure. At high oxygen pressure, the films are randomly oriented, whereas, at low oxygen pressures they are well oriented along [0 0 1] axis for Si substrates and along [1 0 3] axis for glass substrates. A honeycomb structure is obtained at low oxygen pressures, whereas microcrystalline structures were obtained at high oxygen pressures. The effect of oxygen pressure on film transparency, band gap E{sub g} and Urbach energies was investigated.

  18. Pulsed laser deposition of chromium-doped zinc selenide thin films for mid-infrared applications

    Science.gov (United States)

    Williams, J. E.; Camata, R. P.; Fedorov, V. V.; Mirov, S. B.

    2008-05-01

    We have grown Cr doped ZnSe thin films by pulsed laser deposition on GaAs, sapphire and Si substrates through KrF excimer laser ablation of hot-pressed targets containing appropriate stoichiometric mixtures of Zn, Se, and Cr species and hot-pressed ceramic targets made of ZnSe and CrSe powders in vacuum and in an He background environment (10-4 Torr). Deposited films were analyzed using X-ray diffraction to determine crystallinity and energy dispersive X-ray fluorescence to confirm Cr incorporation into the films. Photoluminescence measurements on the films show intracenter Cr2+ emission in the technologically important 2 2.6 μm spectral range.

  19. Microstructural and Electrical Characterization of Barium Strontium Titanate-Based Solid Solution Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition

    Science.gov (United States)

    2003-04-03

    Strontium Titanate-Based Solid Solution Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition DISTRIBUTION: Approved for public...Society H2.4 Microstructural and Electrical Characterization of Barium Strontium Titanate- based Solid Solution Thin Films Deposited on Ceramic...investigated and report the microstructural and electrical characterization of selected barium strontium titanate-based solid solution thin films

  20. Fluence dependent electrical conductivity in aluminium thin films grown by infrared pulsed laser deposition

    Science.gov (United States)

    Rebollar, Esther; Martínez-Tong, Daniel E.; Sanz, Mikel; Oujja, Mohamed; Marco, José F.; Ezquerra, Tiberio A.; Castillejo, Marta

    2016-11-01

    We studied the effect of laser fluence on the morphology, composition, structure and electric conductivity of deposits generated by pulsed laser ablation of a metallic aluminium target in vacuum using a Q-switched Nd:YAG laser (1064 nm, 15 ns). Upon irradiation for one hour at a repetition rate of 10 Hz, a smooth layer of several tens of nanometres, as revealed by atomic force microscopy (AFM) was deposited on glass. Surface chemical composition was determined by X-ray photoelectron spectroscopy, and to study the conductivity of deposits both I-V curves and conductive-AFM measurements were performed. Irradiation at fluences around 2.7 J/cm2 resulted in deposition of amorphous aluminium oxide films. Differently, at higher fluences above 7 J/cm2, the films are constituted by metallic aluminium. Optical emission spectroscopy revealed that highly ionized species are more abundant in the ablation plumes generated at higher fluences. The results demonstrate the possibility to control by PLD the metal or dielectric character of the films.

  1. Synthesis of functionally graded bioactive glass-apatite multistructures on Ti substrates by pulsed laser deposition

    Science.gov (United States)

    Tanaskovic, D.; Jokic, B.; Socol, G.; Popescu, A.; Mihailescu, I. N.; Petrovic, R.; Janackovic, Dj.

    2007-12-01

    Functionally graded glass-apatite multistructures were synthesized by pulsed laser deposition on Ti substrates. We used sintered targets of hydroxyapatite Ca 10(PO 4) 6(OH) 2, or bioglasses in the system SiO 2-Na 2O-K 2O-CaO-MgO-P 2O 5 with SiO 2 content of either 57 wt.% (6P57) or 61 wt.% (6P61). A UV KrF* ( λ = 248 nm, τ > 7 ns) excimer laser source was used for the multipulse laser ablation of the targets. The hydroxyapatite thin films were obtained in H 2O vapors, while the bioglass layers were deposited in O 2. Thin films of 6P61 were deposited in direct contact with Ti, because Ti and this glass have similar thermal expansion behaviors, which ensure good bioglass adhesion to the substrate. This glass, however, is not bioactive, so yet more depositions of 6P57 bioglass and/or hydroxyapatite thin films were performed. All structures with hydroxyapatite overcoating were post-treated in a flux of water vapors. The obtained multistructures were characterized by various techniques. X-ray investigations of the coatings found small amounts of crystalline hydroxyapatite in the outer layers. The scanning electron microscopy analyses revealed homogeneous coatings with good adhesion to the Ti substrate. Our studies showed that the multistructures we had obtained were compatible with further use in biomimetic metallic implants with glass-apatite coating applications.

  2. Structural and optical properties of manganese oxide thin films deposited by pulsed laser deposition at different substrate temperatures

    Science.gov (United States)

    Jamil, H.; Khaleeq-ur-Rahman, M.; Dildar, I. M.; Shaukat, Saima

    2017-09-01

    We report the use of pulsed laser deposition (PLD) to grow manganese oxide thin films at a fixed low oxygen pressure at different temperatures on silicon (1 0 0) substrates. Structural properties of the thin films were examined using x-ray diffraction and Fourier transform infrared spectroscopy. Surface morphology and topography of the films was determined using atomic force microscopy and optical microscopy, while optical properties of the thin films were studied using spectroscopic ellipsometry. It was found that PLD is a convenient technique to deposit different phases of manganese oxide by tuning the deposition temperature. All measured physical properties such as morphology, topography, crystallite size, and optical band gap were clearly dependent on the substrate temperature chosen.

  3. Mechanism of the formation of metal nanoclusters during pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Pushkin, M.A. [Moscow Engineering Physics Institute, 31 Kashirskoe chausse, 115409 Moscow (Russian Federation); Lebid' ko, V.V. [Moscow Engineering Physics Institute, 31 Kashirskoe chausse, 115409 Moscow (Russian Federation); Borman, V.D. [Moscow Engineering Physics Institute, 31 Kashirskoe chausse, 115409 Moscow (Russian Federation); Tronin, V.N. [Moscow Engineering Physics Institute, 31 Kashirskoe chausse, 115409 Moscow (Russian Federation); Troyan, V.I. [Moscow Engineering Physics Institute, 31 Kashirskoe chausse, 115409 Moscow (Russian Federation); Smurov, I. [Ecole Nationale d' Ingenieurs de Saint Etienne, 58 rue Jean Parot, 42023 St-Etienne (France)]. E-mail: smurov@enise.fr

    2006-04-30

    The geometrical structure of Au, Ni, Co and Cr nanoclusters self-assembled on NaCl and HOPG surfaces under pulsed laser deposition (PLD) has been experimentally investigated. The PLD technique is characterized by an extremely high instantaneous deposition rate. Unlike for the thermal evaporation (TE) process, formation of fractal nanoclusters under PLD conditions has been observed with scanning tunneling microscopy (STM). The driving mechanism for this phenomenon occurring at high deposition rate is thought to be the evolution of the initial interacting-adatom states in a system far from thermodynamic equilibrium. The obtained results can be explained by proposing a new mechanism of condensed phase formation under the conditions of strong deviation from thermodynamic equilibrium.

  4. Metallization of bacterial surface layer by cross-beam pulsed laser deposition

    Science.gov (United States)

    Pompe, Wolfgang; Mertig, Michael; Kirsch, Remo; Gorbunov, Andre A.; Sewing, Andreas; Engelhardt, Harald; Mensch, Axel

    1996-04-01

    We present first results on thin film metal deposition on the regular bacterial surface layer of Sporsarcina urea by pulsed laser deposition. To prevent structural damage of the biological specimen a recently developed cross beam technique is applied providing an effective filtering of the most energetic plasma particles. The deposited films are examined by low voltage scanning electron microscopy. The surface profile of the S-layer adsorbed onto mica substrate was investigated by atomic force microscopy. A lattice constant of 13.2 nm has been measured. The lattice parameters and the structural appearance of the protein layer is in reasonable agreement with the results of an electron microscopical 3D structural analysis.

  5. Research Update: Stoichiometry controlled oxide thin film growth by pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    Rik Groenen

    2015-07-01

    Full Text Available The oxidation of species in the plasma plume during pulsed laser deposition controls both the stoichiometry as well as the growth kinetics of the deposited SrTiO3 thin films, instead of the commonly assumed mass distribution in the plasma plume and the kinetic energy of the arriving species. It was observed by X-ray diffraction that SrTiO3 stoichiometry depends on the composition of the background gas during deposition, where in a relative small pressure range between 10−2 mbars and 10−1 mbars oxygen partial pressure, the resulting film becomes fully stoichiometric. Furthermore, upon increasing the oxygen (partial pressure, the growth mode changes from 3D island growth to a 2D layer-by-layer growth mode as observed by reflection high energy electron diffraction.

  6. Pulsed laser deposition of tungsten carbide thin films on silicon (100) substrate

    Science.gov (United States)

    Suda, Y.; Nakazono, T.; Ebihara, K.; Baba, K.

    1997-01-01

    A method of synthesizing tungsten carbide (WC) thin films by a pulsed YAG laser deposition is investigated. WC thin films are deposited on silicon (100) substrates by using WC5%Co alloy targets. Glancing angle X-ray diffraction shows that the strong peaks of W 2C appear at the substrate temperature of 500°C. Beside the strong peaks of W 2C, weak peaks of WC and W 3Co 3C appear at the substrate temperature of 650°C. Auger electron spectroscopy shows that the almost stoichiometric WC films are deposited at the methane gas pressure of 1.0 Pa. Morphological features of the samples have been obtained by employing the technique of scanning electron microscopy. X-ray photoelectron spectroscopy has been used to obtain structural and compositional information about the samples.

  7. Research Update: Stoichiometry controlled oxide thin film growth by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Groenen, Rik; Smit, Jasper; Orsel, Kasper; Vailionis, Arturas; Bastiaens, Bert; Huijben, Mark; Boller, Klaus; Rijnders, Guus; Koster, Gertjan, E-mail: g.koster@utwente.nl [Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands)

    2015-07-01

    The oxidation of species in the plasma plume during pulsed laser deposition controls both the stoichiometry as well as the growth kinetics of the deposited SrTiO{sub 3} thin films, instead of the commonly assumed mass distribution in the plasma plume and the kinetic energy of the arriving species. It was observed by X-ray diffraction that SrTiO{sub 3} stoichiometry depends on the composition of the background gas during deposition, where in a relative small pressure range between 10{sup −2} mbars and 10{sup −1} mbars oxygen partial pressure, the resulting film becomes fully stoichiometric. Furthermore, upon increasing the oxygen (partial) pressure, the growth mode changes from 3D island growth to a 2D layer-by-layer growth mode as observed by reflection high energy electron diffraction.

  8. Role of laser pulse duration and gas pressure in deposition of AlN thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gyorgy, Eniko; Ristoscu, Carmen; Mihailescu, I. N.; Klini, Argyro; Vainos, N.; Fotakis, C.; Ghica, C.; Schmerber, G.; Faerber, J.

    2001-07-01

    We investigated the relative merits and limits of pulsed laser deposition from AlN targets in vacuum and low-pressure nitrogen in obtaining stoichiometric and crystalline aluminum nitride thin films. We used two UV excimer laser sources ({lambda}=248 nm): a nanosecond system ({tau}{sub FWHM}=30 ns) and, a subpicosecond ({tau}{sub FWHM}=450 fs) system. The obtained structures were characterized by x-ray diffraction, electron microscopy in cross section, selected area electron diffraction, and profilometry. We demonstrated that the best results are obtained with the sub-ps laser source in vacuum and in low pressure nitrogen when the AlN thin films are very pure, crystalline, clearly exhibiting a tendency to epitaxy. Metallic Al is present in the films deposited with the ns laser source. We believe this is an effect of the gradual decomposition of AlN inside the crater on the target surface under multipulse laser irradiation. {copyright} 2001 American Institute of Physics.

  9. Micrometric rods grown by nanosecond pulsed laser deposition of boron carbide

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Quintas, Ignacio; Oujja, Mohamed; Sanz, Mikel; Benitez-Cañete, Antonio [Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Chater, Richard J. [Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Cañamares, Maria Vega [Instituto de Estructura de la Materia, CSIC, Serrano 119, 28006 Madrid (Spain); Marco, José F. [Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Castillejo, Marta, E-mail: marta.castllejo@iqfr.csic.es [Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)

    2015-02-15

    Highlights: • Micrometric rods obtained by ns pulsed laser deposition of boron carbide at 1064 and 266 nm. • At 1064 nm microrods display crystalline polyhedral shape with sharp edges and flat sides. • Microrods consist of a mixture of boron, boron oxide, boron carbide and aliphatic hydrocarbons. - Abstract: Micrometric size rods have been fabricated via pulsed laser deposition in vacuum from boron carbide targets using nanosecond pulses of 1064 and 266 nm and room temperature Si (1 0 0) substrates. Morphological, structural and chemical characterization of the microrods was made by applying scanning electron microscopy, focussed ion beam microscopy coupled to secondary ion mass spectrometry, X-ray diffraction, X-ray photoelectron spectroscopy and micro-Raman spectroscopy. Ablation at 1064 nm favours the formation of microrods with high aspect ratio, sharp edges and pyramidal tips, typically 10 μm long with a cross section of around 2 μm × 2 μm. Differently, at 266 nm the microrods are of smaller size and present a more globular aspect. The analyses of the microrods provide information about their crystalline nature and composition, based on a mixture which includes boron, boron oxide and boron carbide, and allows discussion of the wavelength dependent growth mechanisms involved.

  10. Physical properties of a non-transparent cadmium oxide thick film deposited at low fluence by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Quiñones-Galván, J.G., E-mail: erk_183@hotmail.com [Departamento de Física, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, Guadalajara, Jalisco C.P. 44430 (Mexico); Lozada-Morales, R. [Facultad de Ciencias Físico-Matemáticas, Postgrado en Física Aplicada, Benemérita Universidad Autónoma de Puebla, Av. 14 sur y Av. San Claudio, Col. San Manuel, Puebla (Mexico); Jiménez-Sandoval, S. [Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Querétaro, Apartado Postal 1-798 Querétaro, Qro 76001 (Mexico); Camps, Enrique [Departamento de Física, Instituto Nacional de Investigaciones Nucleares, Apartado postal 18-1027, México D.F. C.P. 11801 (Mexico); and others

    2016-04-15

    Highlights: • A non-transparent cadmium oxide film has been deposited by pulsed laser deposition. • The CdO film is polycrystalline and highly oriented in the (2 0 0) direction. • Thermal treatment was applied in order to see the effect on its physical properties. - Abstract: A stable non-transparent CdO film was grown by pulsed laser deposition. The sample was thermally annealed at 500 °C in air. A (2 0 0) highly oriented polycrystalline film was obtained. The annealed sample has not preferred orientation. Scanning electron micrographs show a grain size reduction for the annealed sample. By Raman spectroscopy, the defects related second order vibrational modes of CdO were observed. Chemical composition analysis shows the presence of CdO together with a substoichiometric CdO{sub x} phase for the as-grown sample. For the annealed sample a compensation of oxygen vacancies was observed. Electrical resistivity measurements give a value of 8.602 × 10{sup −4} (Ω cm) for the as-grown film. For the annealed sample the electrical resistivity increased to a value of 9.996 × 10{sup −3} (Ω cm). Zero transmission has never been reported for CdO films. The photoluminescence spectra were measured in order to shed some light on the origin of the zero transmission.

  11. Deposition of NbC thin films by pulsed laser ablation

    Science.gov (United States)

    Duhalde, S.; Colaco, R.; Audebert, F.; Perrone, A.; Zocco, A.

    Niobium carbide thin films were prepared by pulsed laser ablation of a stoichiometric NbC target. XeCl (308 nm, 30 ns) and Nd:YAG (266 nm, 5 ns) lasers operating at a repetition rate of 10 Hz were used. Films were deposited on Si (100) substrates at room temperature either in vacuum or in an argon atmosphere (2×10-1 mbar). Different laser fluences (2, 4 and 6 J/cm2) and different numbers of pulses (1×104, 2×104 and 4×104) were tested. For the first time, NbC films were prepared through a clean procedure without the addition of a hydrocarbon atmosphere. The phase constitution of the films, unit cell size, mean crystallite dimensions and preferred orientation are determined as a function of deposition conditions by X-ray diffraction. Complementary morphological and structural analysis of the films were performed by scanning electron microscopy, atomic force microscopy and Rutherford backscattering spectroscopy.

  12. Pulsed laser deposition of hydroxyapatite on titanium substrate with titania interlayer.

    Science.gov (United States)

    Rajesh, P; Muraleedharan, C V; Komath, Manoj; Varma, Harikrishna

    2011-03-01

    Pulsed laser deposition (PLD) has been used to deposit hydroxyapatite (HA) ceramic over titanium substrate with an interlayer of titania. PLD has been identified as a potential candidate for bioceramic coatings over metallic substrates to be used as orthopedic and dental implants because of better process control and preservation of phase identity of the coating component. However, direct deposition of hydroxyapatite on titanium at elevated temperature results in the formation of natural oxide layer along with some perovskites like calcium titanate at the interface. This leads to easy debonding of ceramic layer from the metal and thereby affecting the adhesion strength. In the present study, adherent and stable HA coating over Ti6Al4V was achieved with the help of an interlayer of titania. The interlayer was made to a submicron level and HA was deposited consecutively to a thickness of around one micron by exposing to laser ablation at a substrate temperature of 400°C. The deposited phase was identified to be phase pure HA by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, and inductively coupled plasma spectrometry. The mechanical behavior of coating evaluated by scratch test indicates that the adhesion strength of HA coating was improved with the presence of titania interlayer.

  13. ZnO thin films on single carbon fibres fabricated by Pulsed Laser Deposition (PLD)

    Science.gov (United States)

    Krämer, André; Engel, Sebastian; Sangiorgi, Nicola; Sanson, Alessandra; Bartolomé, Jose F.; Gräf, Stephan; Müller, Frank A.

    2017-03-01

    Single carbon fibres were 360° coated with zinc oxide (ZnO) thin films by pulsed laser deposition using a Q-switched CO2 laser with a pulse duration τ ≈ 300 ns, a wavelength λ = 10.59 μm, a repetition frequency frep = 800 Hz and a peak power Ppeak = 15 kW in combination with a 3-step-deposition technique. In a first set of experiments, the deposition process was optimised by investigating the crystallinity of ZnO films on silicon and polished stainless steel substrates. Here, the influence of the substrate temperature and of the oxygen partial pressure of the background gas were characterised by scanning electron microscopy and X-ray diffraction analyses. ZnO coated carbon fibres and conductive glass sheets were used to prepare photo anodes for dye-sensitised solar cells in order to investigate their suitability for energy conversion devices. To obtain a deeper insight of the electronic behaviour at the interface between ZnO and substrate I-V measurements were performed.

  14. Electronic and optical studies of pulse laser deposited ZnO/NiO bilayer film

    Science.gov (United States)

    Baraskar, P.; Dar, T. A.; Choudhary, R. J.; Sen, P. K.; Sen, P.

    2016-10-01

    We report the structural, optical and electronic properties of polycrystalline ZnO and NiO thin films and amorphous ZnO/NiO bilayer film, prepared by pulsed laser deposition technique. Despite of the presence of both Zn and Ni in +2 state in the bilayer film, the grown bilayer shows no reflections (in XRD) corresponding to ZnO or NiO. The difference in crystal structure of ZnO and NiO leads to the strain in the grown bilayer film. An increase in the band gap has been observed in bilayer film which can be attributed to the amorphous nature of the structure.

  15. Growth of ZnO thin films on GaAs by pulsed laser deposition

    OpenAIRE

    Craciun, V.; Elders, J.; Gardeniers, J.G.E.; Geretovsky, J.; Boyd, Ian W.

    1995-01-01

    ZnO thin films have been grown on GaAs substrates using the pulsed laser deposition technique with or without a photodeposited SiO2 buffer layer. The presence of the SiO2 layer has a beneficial effect on the crystalline quality of the grown ZnO films. Highly c-axis oriented ZnO films having a full width at half maximum value of the (002) X-ray diffraction line of less than 0.13 ° have been grown on such buffer layers at a substrate temperature of only 350 °C.

  16. Nanostructured molybdenum carbide thin films obtained by femtosecond pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Teghil, Roberto; De Bonis, Angela [Dipartimento di Chimica ' ' A.M. Tamburro' ' , Universita della Basilicata, Potenza (Italy); IMIP-U.O.S. di Potenza, Consiglio Nazionale delle Ricerche, Tito (Italy); Galasso, Agostino; Sansone, Maria [Dipartimento di Chimica ' ' A.M. Tamburro' ' , Universita della Basilicata, Potenza (Italy); Rau, Julietta V. [ISM, Consiglio Nazionale delle Ricerche, Rome (Italy); Santagata, Antonio [IMIP-U.O.S. di Potenza, Consiglio Nazionale delle Ricerche, Tito (Italy)

    2012-12-15

    The films obtained by ultra-short pulsed laser deposition of a target of molybdenum carbide, at different substrate temperatures, have been characterized by different techniques, including scanning electron microscopy, micro-Raman spectroscopy and X-ray photoelectron spectroscopy. The results indicate that the films are formed by a large number of particles with nanometric dimensions and are composed mainly of Mo{sub 2}C. The presence of an excess of carbon, found in the films, is probably due the presence of a certain amount of graphite in the target (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. CEMS study on diluted magneto titanium oxide films prepared by pulsed laser deposition

    Science.gov (United States)

    Nomura, K.; Inaba, K.; Iio, S.; Hitosugi, T.; Hasegawa, T.; Hirose, Y.; Homonnay, Z.

    6% 57Fe doped titanium oxide films, prepared by pulsed laser deposition (PLD) on sapphire substrate at 650° under various vacuum conditions, were characterized mainly by conversion electron Mössbauer spectrometry (CEMS). Two magnetic sextets with hyperfine fields 33 and 29 T, and one doublet were observed in the CEMS spectra of Ti02 films prepared under P02=10-6 and 10-8 torr, which showed ferromagnetism at room temperature, whereas only the doublet of paramagnetic Fe3+ species was observed for the film prepared under P02=10-1 torr.

  18. Structural and magnetic properties of Gd/Fe multilayers grown by pulsed laser deposition

    DEFF Research Database (Denmark)

    Kant, K. Mohan; Bahl, Christian Robert Haffenden; Pryds, Nini;

    This work investigates structural and magnetic properties of Gd/Fe multilayered thin films grown by pulsed laser deposition onto Si (001) substrates at room temperature. The Fe layer thickness is varied from 70 to 150 nm and its effect on structural and magnetic properties of Gd/Fe multilayers has...... been explored. The samples have a 10 nm Ag capping layer to prevent oxidation during the processing. Two magnetization saturation plateaus were observed in the magnetization vs field isotherm at 290 K, in parallel configuration and these plateau values correspond to that of MFe and MFe + MGd....

  19. Decoration of silica nanowires with gold nanoparticles through ultra-short pulsed laser deposition

    Science.gov (United States)

    Gontad, F.; Caricato, A. P.; Cesaria, M.; Resta, V.; Taurino, A.; Colombelli, A.; Leo, C.; Klini, A.; Manousaki, A.; Convertino, A.; Rella, R.; Martino, M.; Perrone, A.

    2017-10-01

    The ablation of a metal target at laser energy densities in the range of 1-10 TW/cm2 leads to the generation of nanoparticles (NP) of the ablated material. This aspect is of particular interest if the immobilization of NPs on three-dimensional (3D) substrates is necessary as for example in sensing applications. In this work the deposition of Au NP by irradiation of a Au bulk target with a sub-picosecond laser beam (500 fs; 248 nm; 10 Hz) on 2D (silica and Si(100)) and 3D substrates (silica nanowire forests) is reported for different number of laser pulses (500, 1000, 1500, 2000, 2500). A uniform coverage of small Au NPs (with a diameter of few nm) on both kinds of substrates has been obtained using a suitable number of laser pulses. The presence of spherical droplets, with a diameter ranging from tens of nm up to few μm was also detected on the substrate surface and their presence can be explained by the weak electron-phonon coupling of Au. The optical characterization of the samples on 2D and 3D substrates evidenced the surface plasmon resonance peak characteristic of the Au NPs although further improvements of the size-distribution are necessary for future applications in sensing devices.

  20. Pulsed Laser Deposition of YBa2Cu3Ox with Scanning Beam: Target to Substrate Composition Transfer and Film Structure

    DEFF Research Database (Denmark)

    Mozhaev, Peter; Khoryushin, Alexey; Mozhaeva, Julia

    2017-01-01

    Pulsed laser deposition is often considered a process providing congruent transfer of target composition to the growing film. In fact, many different processes affect compositional preservation, starting from incongruent target ablation, to scattering on the way to the substrate, and to processes...... of the film formation on the substrate surface. We developed a pulsed laser deposition process trying to minimize the compositional deviations due to the scattering by the ambient gas by applying laser beam scanning across the target surface and substitution of oxygen with argon in the chamber during...

  1. Electrical conductivity mechanisms in zinc oxide thin films deposited by pulsed laser deposition using different growth environments

    Energy Technology Data Exchange (ETDEWEB)

    Heluani, S.P. [Laboratorio de Fisica del Solido, Departamento de Fisica, Facultad de Ciencias Exactas y Tecnologia, Universidad Nacional de Tucuman (Argentina)]. E-mail: sperez@herrera.unt.edu.ar; Braunstein, G. [Department of Physics, University of Central Florida, Orlando, FL 32816 (United States); Villafuerte, M. [Laboratorio de Fisica del Solido, Departamento de Fisica, Facultad de Ciencias Exactas y Tecnologia, Universidad Nacional de Tucuman (Argentina); Simonelli, G. [Laboratorio de Fisica del Solido, Departamento de Fisica, Facultad de Ciencias Exactas y Tecnologia, Universidad Nacional de Tucuman (Argentina); Duhalde, S. [Laboratorio de Ablacion Laser, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina)

    2006-12-05

    The mechanisms of electrical conduction in zinc oxide thin films, grown by pulsed laser deposition, have been investigated as a function of preparation conditions. The films were deposited on glass and silicon nitride coated silicon, using oxygen rich, oxygen deficient, or nitrogen atmospheres. The substrates were held at 473 K during deposition, and subsequently cooled down to room temperature in oxygen rich atmosphere of 4 Pa, or oxygen deficient atmosphere of 2 x 10{sup -3} Pa. Films deposited and cooled in an oxygen deficient atmosphere exhibited very high donor concentration, originated in intrinsic defects, and an impurity band related mechanism of conduction. Films deposited under relatively high oxygen pressure were highly resistive and showed, upon ultraviolet light irradiation, grain boundary controlled electrical transport. An enhancement of the conductivity was observed when using a nitrogen atmosphere during the deposition, and oxygen atmosphere during cooling. In this case, the dependence of the conductivity with temperature followed Motts' Law of variable range hopping, characteristic of a material with localized states randomly located in space. Since the density of hopping centers appears to be much larger than the density of nitrogen incorporated in this sample, it is suggested that the nitrogen induces defects in the zinc oxide lattice that behave as localized hopping centers, as well as carrier suppliers, giving rise to the observed conductivity.

  2. Fabrication of arrays of gold islands on self-assembled monolayers using pulsed laser deposition through nanosieves

    NARCIS (Netherlands)

    Speets, Emiel A.; Ravoo, Bart Jan; Roesthuis, Frank J.G.; Vroegindeweij, Frank; Blank, Dave H.A.; Reinhoudt, David N.

    2004-01-01

    Sandwich structures of gold-self-assembled monolayer-gold were prepared by deposition of gold on alkylthiolate self-assembled monolayers on polycrystalline gold, using pulsed laser deposition (PLD) through a nanosieve. The arrays of sandwiches, around 600 nm in diameter, approximately 10 nm high, an

  3. Physical aspects of the pulsed laser deposition technique: The stoichiometric transfer of material from target to film

    DEFF Research Database (Denmark)

    Schou, Jørgen

    2009-01-01

    The physical processes of pulsed laser deposition (PLD) change strongly from the initial light absorption in a target to the final deposition and growth of a film. One of the primary advantages of PLD is the stoichiometric transfer of material from target to a film on a substrate. Even for a stoi...

  4. Rare Earth Doped Gallium Gadolinium Orthogallate Films Prepared by Pulsed Laser Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lancok, J [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic (Czech Republic); Novotny, M [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic (Czech Republic); Garapon, C [LPCML, UMR 5620 CNRS-Universite Claude Bernard Lyon-I, 10 rue Andre Marie Ampere, 69622 Villeurbanne Cedex (France); JelInek, M [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic (Czech Republic)

    2007-04-15

    The decomposition of Gd{sub 3}Ga{sub 5}O{sub 12} single crystal target induced by a KrF excimer laser pulse during the deposition process was observed. This phenomenon was studied ex situ by EDX analyse of ablated target and in situ by Optical Emission Spectroscopy of the laser plasma. The decomposition process depends mainly on the absorption coefficient of the target on the corresponding laser wavelength and oxygen partial pressure in the deposition chamber during laser ablation. Taking into account the differences between absorption coefficients of Pr:Gd{sub 3}Ga{sub 5}O{sub 12} and Yb:Gd{sub 3}Ga{sub 5}O{sub 12} targets the Pr:GdGaO{sub 3} and Yb:GdGaO{sub 3} thin films were successfully fabricated at different oxygen pressures of 1 Pa and 2.5 Pa, respectively. The structural properties of the fabricated films were studied by RBS and XRD.

  5. Amorphous carbon-silicon heterojunctions by pulsed Nd:YAG laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yap, Seong-Shan; Yow, Ho-Kwang [Faculty of Engineering, Multimedia University, Cyberjaya, Selangor 63100 (Malaysia); Tou, Teck-Yong, E-mail: tytou@mmu.edu.m [Faculty of Engineering, Multimedia University, Cyberjaya, Selangor 63100 (Malaysia)

    2009-07-31

    Amorphous carbon (a-C) films were deposited at 10{sup -4} Pa on n-Si (Si-111) and p-Si (Si-100) substrates using a pulsed Nd:YAG laser with fundamental, second- and third-harmonic outputs. These unhydrogenated and undoped a-C films were characterized by visible and UV Raman spectroscopy which indicated the presence of substantial amount of sp{sup 3} hybridized carbon network depending on the laser wavelength. The bulk resistivity in the Au/a-C/indium tin oxide structure varied between (10{sup 9}-10{sup 13}) {Omega} cm - the lowest resistivity was obtained for films deposited by the fundamental laser output at 1064 nm while the highest value was by the third-harmonic laser output at 355 nm. All the a-C/Si heterostructures exhibited a nonlinear current density-voltage characteristic. Under light illumination, by taking into consideration the fill factor of {approx} 0.2 for a-C/n-Si, the conversion efficiency at the highest photovoltage and photocurrent, at an illumination density of 0.175 mW/cm{sup 2} was estimated to be {approx} 0.28%.

  6. Pulsed laser deposition of YBCO films on ISD MgO buffered metal tapes

    CERN Document Server

    Ma, B; Koritala, R E; Fisher, B L; Markowitz, A R; Erck, R A; Baurceanu, R; Dorris, S E; Miller, D J; Balachandran, U

    2003-01-01

    Biaxially textured magnesium oxide (MgO) films deposited by inclined-substrate deposition (ISD) are desirable for rapid production of high-quality template layers for YBCO-coated conductors. High-quality YBCO films were grown on ISD MgO buffered metallic substrates by pulsed laser deposition (PLD). Columnar grains with a roof-tile surface structure were observed in the ISD MgO films. X-ray pole figure analysis revealed that the (002) planes of the ISD MgO films are tilted at an angle from the substrate normal. A small full-width at half maximum (FWHM) of approx 9deg was observed in the phi-scan for ISD MgO films deposited at an inclination angle of 55deg . In-plane texture in the ISD MgO films developed in the first approx 0.5 mu m from the substrate surface, and then stabilized with further increases in film thickness. Yttria-stabilized zirconia and ceria buffer layers were deposited on the ISD MgO grown on metallic substrates prior to the deposition of YBCO by PLD. YBCO films with the c-axis parallel to the...

  7. Thin films deposited by femtosecond pulsed laser ablation of tungsten carbide

    Energy Technology Data Exchange (ETDEWEB)

    De Bonis, A. [Dipartimento di Chimica ' A.M. Tamburro' , Universita della Basilicata, Via dell' Ateneo Lucano 10, 85100 Potenza (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali - INSTM, Via G. Giusti 9, 00121 Florence (Italy); Teghil, R., E-mail: roberto.teghil@unibas.it [Dipartimento di Chimica ' A.M. Tamburro' , Universita della Basilicata, Via dell' Ateneo Lucano 10, 85100 Potenza (Italy); Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali - INSTM, Via G. Giusti 9, 00121 Florence (Italy); Santagata, A. [Istituto Metodologie Inorganiche e Plasmi, CNR, Unita di Potenza, via S. Loja, 85050 Tito Scalo PZ (Italy); Galasso, A. [Dipartimento di Chimica ' A.M. Tamburro' , Universita della Basilicata, Via dell' Ateneo Lucano 10, 85100 Potenza (Italy); Rau, J.V. [Istituto di Struttura della Materia, CNR, Via del Fosso del Cavaliere 100, 00133 Rome (Italy)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We have deposited amorphous tungsten carbide films by ultra-short PLD. Black-Right-Pointing-Pointer In the films different W-C phases are present. Black-Right-Pointing-Pointer The films are formed mainly by particles with nanometric size. Black-Right-Pointing-Pointer We propose that the particles are directly ejected from the target. - Abstract: Ultra-short Pulsed Laser Deposition has been applied to the production of thin films from a tungsten carbide target. The gaseous phase obtained by the laser ablation shows a very weak primary plume, in contrast with a very strong secondary one. The deposited films, investigated by Scanning Electron Microscopy, Atomic Force Microscopy, X-Ray Photoelectron Spectroscopy and X-Ray Diffraction, present a mixture of WC and other phases with lower carbon content. All films are amorphous, independently from the substrate temperature. The characteristics of the deposits have been explained in terms of thermal evaporation and cooling rate of molten particles ejected from the target.

  8. Oxidation of ZnO thin films during pulsed laser deposition process

    Indian Academy of Sciences (India)

    E De Posada; L Moreira; J Pérez De La Cruz; M Arronte; L V Ponce; T Flores; J G Lunney

    2013-06-01

    Pulsed laser deposition of ZnO thin films, using KrF laser, is analysed. The films were deposited on (001) sapphire substrates at 400 °C, at two different oxygen pressures (0.3 and 0.4 mbar) and two different target–substrate distances (30 and 40 mm). It is observed that in order to obtain good quality in the photoluminescence of the films, associated with oxygen stoichiometry, it is needed to maximize the time during which the plasma remains in contact with the growing film (plasma residence time), which is achieved by selecting suitable combinations of oxygen pressures and target to substrate distances. It is also discussed that for the growth parameters used, the higher probability for ZnO films growth results from the oxidation of Zn deposited on the substrate and such process takes place during the time that the plasma is in contact with the substrate. Moreover, it is observed that maximizing the plasma residence time over the growing film reduces the rate of material deposition, favouring the surface diffusion of adatoms, which favours both Zn–O reaction and grain growth.

  9. Helium-Charged Titanium Films Deposited by Pulsed Laser Deposition in an Electron-Cyclotron-Resonance Helium Plasma Environment

    Institute of Scientific and Technical Information of China (English)

    金钦华; 胡佩钢; 凌浩; 吴嘉达; 施立群; 周筑颖

    2003-01-01

    Titanium thin films incorporated with helium are produced by pulsed laser deposition in an electron cyclotron resonance helium plasma environment. Helium is distributed evenly in the film and a relatively high He/Ti atomic ratio (~ 20%) is obtained from the proton backscattering spectroscopy. This high concentration ofhelium leads to a surface blistering which is observed by scanning electron microscopy. Laser repetition rate has little influence on film characters. Substrate bias voltage is also changed for the helium incorporating mechanism study, and this is a helium ion implantation process during the film growth. Choosing suitable substrate bias voltage, one can avoid the damage produced by ion implantation, which is always present in general implantation case.

  10. Growth of centimeter-scale atomically thin MoS2 films by pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    Gene Siegel

    2015-05-01

    Full Text Available We are reporting the growth of single layer and few-layer MoS2 films on single crystal sapphire substrates using a pulsed-laser deposition technique. A pulsed KrF excimer laser (wavelength: 248 nm; pulse width: 25 ns was used to ablate a polycrystalline MoS2 target. The material thus ablated was deposited on a single crystal sapphire (0001 substrate kept at 700 °C in an ambient vacuum of 10−6 Torr. Detailed characterization of the films was performed using atomic force microscopy (AFM, Raman spectroscopy, UV-Vis spectroscopy, and photoluminescence (PL measurements. The ablation of the MoS2 target by 50 laser pulses (energy density: 1.5 J/cm2 was found to result in the formation of a monolayer of MoS2 as shown by AFM results. In the Raman spectrum, A1g and E12g peaks were observed at 404.6 cm−1 and 384.5 cm−1 with a spacing of 20.1 cm−1, confirming the monolayer thickness of the film. The UV-Vis absorption spectrum exhibited two exciton absorption bands at 672 nm (1.85 eV and 615 nm (2.02 eV, with an energy split of 0.17 eV, which is in excellent agreement with the theoretically predicted value of 0.15 eV. The monolayer MoS2 exhibited a PL peak at 1.85 eV confirming the direct nature of the band-gap. By varying the number of laser pulses, bi-layer, tri-layer, and few-layer MoS2 films were prepared. It was found that as the number of monolayers (n in the MoS2 films increases, the spacing between the A1g and E12g Raman peaks (Δf increases following an empirical relation, Δ f = 26 . 45 − 15 . 42 1 + 1 . 44 n 0 . 9 cm − 1 .

  11. High quality ZnS/Au/ZnS transparent conductive tri-layer films deposited by pulsed laser deposition

    Science.gov (United States)

    Wang, Caifeng; Li, Qingshan; Wang, Jisuo; Zhang, Lichun; Zhao, Fengzhou; Dong, Fangying

    2016-07-01

    ZnS/Au/ZnS tri-layer films were deposited on quartz glass substrates by pulsed laser deposition. The influence of Au layer thickness on optical and electrical properties of the tri-layer ZnS/Au/ZnS was studied. X-ray diffractometer (XRD) and scanning electron microscope were employed to characterize the crystalline structure and surface morphology of the tri-layer films. Hall measurements, ultraviolet and visible spectrophotometer, four-point probe were used to explore the optoelectronic properties of the ZnS/Au/ZnS. The increase of Au layer thickness resulted in the decreased resistivity, the increased carrier concentration, and the declined transmittance in the visible light region.

  12. Structural Transition in SrZnO Laser Pulse Deposited Alloy

    Directory of Open Access Journals (Sweden)

    Albrithen H. A.

    2017-03-01

    Full Text Available We have discovered a structural transition for the SrZnO alloy films from a wurtzite to a rock-salt structure, leading to a reduction in the (112̲0/(0001 surface energy ratio. The films were grown by pulsed laser deposition using different SrO ratios, x. We have revealed that growth at a higher temperature, 750°C, resulted in a sharp 0002 peak at a low SrO content (5%, whereas growth at a higher SrO content (10% resulted in a non-crystalline film with minute crystallites with a (112̲0 orientation. Generally the crystallinity decreased as the SrO content increased. No results obtained for the crystalline films showed any orientation of significant peaks besides the peak attributed to the (0001 plane, suggesting epitaxial growth. Optical measurements showed difference in transmission widows of alloys with different SrO percentage, and this was correlated to SrO influence on growth mode as indicated by scanning electron imaging. The studied SrZnO films, with SrO/(SrO + ZnO ≤ 0.25, were grown by pulsed laser deposition using different SrO ratios, x. The effects of temperature and oxygen pressure during growth on the films’ structural properties were investigated. XRD results indicate that the film crystallinity was improved as the temperature and O2 pressure increased up to 650°C and 0.5 Torr, respectively.

  13. Towards new binary compounds: Synthesis of amorphous phosphorus carbide by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hart, Judy N., E-mail: Judy.Hart@bristol.ac.uk [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); May, Paul W.; Allan, Neil L. [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Hallam, Keith R. [Interface Analysis Centre, University of Bristol, 121 St. Michaels Hill, Bristol BS2 8BS (United Kingdom); Claeyssens, Frederik [Kroto Research Institute, Department of Materials Science and Engineering, University of Sheffield, Broad Lane, Sheffield S3 7HQ (United Kingdom); Fuge, Gareth M.; Ruda, Michelle [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Heard, Peter J. [Interface Analysis Centre, University of Bristol, 121 St. Michaels Hill, Bristol BS2 8BS (United Kingdom)

    2013-02-15

    We have recently undertaken comprehensive computational studies predicting possible crystal structures of the as yet unknown phosphorus carbide as a function of composition. In this work, we report the synthesis of amorphous phosphorus-carbon films by pulsed laser deposition. The local bonding environments of carbon and phosphorus in the synthesised materials have been analysed by x-ray photoelectron spectroscopy; we have found strong evidence for the formation of direct P-C bonding and hence phosphorus carbide. There is a good agreement between the bonding environments found in this phosphorus carbide material and those predicted in the computational work. In particular, the local bonding environments are consistent with those found in the {beta}-InS-like structures that we predict to be low in energy for phosphorus:carbon ratios between 0.25 and 1. Highlights: Black-Right-Pointing-Pointer We have synthesised amorphous phosphorus-carbon films by pulsed laser deposition. Black-Right-Pointing-Pointer X-ray photoelectron spectroscopy results indicate formation of direct P-C bonds and hence phosphorus carbide. Black-Right-Pointing-Pointer Local bonding environments are consistent with those in predicted structures.

  14. Frictional Properties of UV illuminated ZnO Thin Films Grown by Pulsed Laser Deposition

    Science.gov (United States)

    Chiu, Hsiang-Chih; Chang, Huan-Pu; Lo, Fang-Yu; Yeh, Yu-Ting; Department of Physics, National Taiwan Normal University Collaboration

    Zinc Oxide (ZnO) nanostructures have potential applications in nano-electro-mechanical systems (NEMS) due to their unique physical properties. ZnO is also an excellent lubricant and hence a promising candidate for protective coatings in NEMS. By means of atomic force microscopy (AFM), we have investigated the frictional properties of ZnO thin films prepared by pulsed laser deposition technique. In addition, UV illumination is used to convert the surface wettability of ZnO thin films from being more hydrophobic to superhydrophilic via the photo-catalyst effect. We found that the frictional properties of the UV illuminated, superhydrophilic ZnO surface are strongly dependent on the environment humidity. While for hydrophobic ZnO, no such dependence is found. The observed frictional behaviors can be explained by the interplay between the surface roughness, environmental humidity and the presence of nanoscale capillary condensation forming between surface asperities at the tip-ZnO contact. Our results might find applications in future ZnO related NEMS. Frictional Properties of UV illuminated ZnO Thin Films Grown by Pulsed Laser Deposition.

  15. Effect of target density on the growth and properties of YGBCO thin films deposited by pulsed laser deposition

    Science.gov (United States)

    Liu, Linfei; Li, Yiejie; Wu, Xiang; Yao, Yanjie; Wang, Menglin; Wang, Binbin

    2016-12-01

    Some works found that target density had not a large effects on the superconducting or structural properties of YBa2Cu3O7-δ (YBCO) films prepared by pulsed laser deposition. However, the possible effect of target density on the Y0.5Gd0.5Ba2Cu3O7-δ (YGBCO) is not clear. In this paper, YGBCO thin films were deposited on flexible metal substrates by pulsed laser deposition using target with different densities. The density of each YGBCO target was varied from to 4.0 g/cm3 to 5.5 g/cm3. The aim of this study was to determine the relationship between the microstructure and superconducting properties of YGBCO films as a function of the target density. The film structures were examined by X-ray diffraction and field emission scanning electron microscopy. The superconducting properties of the YGBCO films were evaluated using the conventional four-probe method and PPMS. It was found that all the YGBCO films had pure c-axis orientation. The target density had effect on the surface morphology and superconducting properties of the YGBCO thin films. With increasing target density, the pore became larger and the distribution density and size of the particles became higher and larger, and the critical current Ic decreased. The YGBCO film deposited at a target density of 4.0 g/cm3 exhibited the highest critical current density Jc of 5.4 MA/cm2 at 77 K and self-field, 47.2 MA/cm2 at 0 T and 8.8 MA/cm2 at 9 T at 4.2 K and B//c.

  16. Pressure effects during pulsed-laser deposition of barium titanate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalo, J.; Afonso, C.N. [Consejo Superior de Investigaciones Cientificas, Madrid (Spain). Inst. de Optica; Gomez San Roman, R.; Perez Casero, R. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, 28049 Cantoblanco, Madrid (Spain); Perriere, J. [Groupe de Physique des Solides, Universites Paris VII et VI, URA 17 du CNRS, Tour 23, 2 Place Jussieu, 75251 Paris Cedex 05 (France)

    1998-05-01

    The composition and homogeneity of barium titanate films grown by pulsed-laser deposition at different substrate temperatures (room temperature, 700 C) and gas environments (O{sub 2},Ar) in a broad pressure range (10{sup -7}-1 mbar) are correlated to the plasma expansion dynamics. It is found that the deposited films present an excess of Ba in the intermediate pressure range (10{sup -2}

  17. Chalcogenide-based thin film sensors prepared by pulsed laser deposition technique

    Science.gov (United States)

    Schubert, J.; Schöning, M. J.; Schmidt, C.; Siegert, M.; Mesters, St.; Zander, W.; Kordos, P.; Lüth, H.; Legin, A.; Mourzina, Yu. G.; Seleznev, B.; Vlasov, Yu. G.

    One advantage of the pulsed laser deposition (PLD) method is the stoichiometric transfer of multi-component target material to a given substrate. This advantage of the PLD determined the choice to prepare chalco-genide-based thin films with an off-axis geometry PLD. Ag-As-S and Cu-Ag-As-Se-Tetargets were used to deposit thin films on Si substrates for an application as a heavy metal sensing device. The films were characterized by means of Rutherford backscattering spectrometry (RBS), transmission electron microscopy (TEM), and electrochemical measurements. The same stoichiometry of the films and the targets was confirmed by RBS measurements. We observed a good long-term stability of more than 60 days and a nearly Nernstian sensitivity towards Pb and Cu, which is comparable to bulk sensors.

  18. Sims Characterisation of ZnO Layer Prepared By Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Andrej Vincze

    2005-01-01

    Full Text Available New material development requires new technologies to create and prepare basic material for semiconductor industry and device applications. Materials have given properties, which exhibit particulary small tolerances. One of the most important and promising material is recently ZnO. ZnO has specific properties for near UV emission and absorption optical devices. The pulsed laser deposition (PLD is one of the methods to prepare this type of material. The aim of this paper is to compare properties of ZnO layers deposited from pure Zn target in oxygen atmosphere and the analysis of their surface properties by secondary ion mass spectroscopy (SIMS, atomic force microscopy (AFM and scanning electron microscopy (SEM.

  19. Thickness Influence on In Vitro Biocompatibility of Titanium Nitride Thin Films Synthesized by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Liviu Duta

    2016-01-01

    Full Text Available We report a study on the biocompatibility vs. thickness in the case of titanium nitride (TiN films synthesized on 410 medical grade stainless steel substrates by pulsed laser deposition. The films were grown in a nitrogen atmosphere, and their in vitro cytotoxicity was assessed according to ISO 10993-5 [1]. Extensive physical-chemical analyses have been carried out on the deposited structures with various thicknesses in order to explain the differences in biological behavior: profilometry, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS, X-ray diffraction and surface energy measurements. XPS revealed the presence of titanium oxynitride beside TiN in amounts that vary with the film thickness. The cytocompatibility of films seems to be influenced by their TiN surface content. The thinner films seem to be more suitable for medical applications, due to the combined high values of bonding strength and superior cytocompatibility.

  20. Structural modification of titanium surface by octacalcium phosphate via Pulsed Laser Deposition and chemical treatment

    Directory of Open Access Journals (Sweden)

    I.V. Smirnov

    2017-06-01

    Full Text Available In the present study, the Pulsed Laser Deposition (PLD technique was applied to coat titanium for orthopaedic and dental implant applications. Calcium carbonate (CC was used as starting coating material. The deposited CC films were transformed into octacalcium phosphate (OCP by chemical treatments. The results of X-ray diffraction (XRD, Raman, Fourier Transform Infrared Spectroscopy (FTIR and scanning electron microscopy (SEM studies revealed that the final OCP thin films are formed on the titanium surface. Human myofibroblasts from peripheral vessels and the primary bone marrow mesenchymal stromal cells (BMMSs were cultured on the investigated materials. It was shown that all the investigated samples had no short-term toxic effects on cells. The rate of division of myofibroblast cells growing on the surface and saturated BMMSs concentration for the OCP coating were about two times faster than of cells growing on the CC films.

  1. Apparatus and method for pulsed laser deposition of materials on wires and pipes

    Science.gov (United States)

    Fernandez, Felix E. (Inventor)

    2003-01-01

    Methods and apparatuses are disclosed which allow uniform coatings to be applied by pulsed laser deposition (PLD) on inner and outer surfaces of cylindrical objects, such as rods, pipes, tubes, and wires. The use of PLD makes this technique particularly suitable for complex multicomponent materials, such as superconducting ceramics. Rigid objects of any length, i.e., pipes up to a few meters, and with diameters from less than 1 centimeter to over 10 centimeters can be coated using this technique. Further, deposition is effected simultaneously onto an annular region of the pipe wall. This particular arrangement simplifies the apparatus, reduces film uniformity control difficulties, and can result in faster operation cycles. In addition, flexible wires of any length can be continuously coated using the disclosed invention.

  2. Diffusion barrier performance of pulsed laser deposited amorphous tungsten carbide films

    Science.gov (United States)

    Ghaisas, Smita

    1991-12-01

    The performance of pulsed laser deposited tungsten carbide films as diffusion barriers between a Si substrate and an Al overlayer has been investigated. Four-point probe measurement of resistance is employed to monitor the electrical stability of the Al/WC/Si metallization schemes upon thermal annealing in a vacuum for 30 min in a temperature range from 100 to 500 °C. The Glancing angle x-ray diffraction technique has been used to characterize the as-deposited as well as annealed samples. To study the metallurgical interaction between Al overlayer and the barrier film, experiments on isothermal annealings are carried out. The data obtained have been used to estimate the activation energy for the formation of the intermetallic compound WAl12. Morphological features of the annealed samples have been obtained by employing the technique of scanning electron microscopy.

  3. Field emission properties of amorphous GaN ultrathin films fabricated by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    WANG FengYing; WANG RuZhi; ZHAO Wei; SONG XueMei; WANG Bo; YAN Hui

    2009-01-01

    Amorphous gallium nitride (a-GaN) films with thicknesses of 5 and 300 nm are deposited on n-Si (100) substrates by pulsed laser deposition (PLD), and their field emission (FE) properties are studied. It shows that compared with thicker (300 nm) a-GaN film, better FE performance is obtained on ultrathin (5 nm) a-GaN film with a threshold field of 0.78 V/μm, which is the lowest value ever reported. Furthermore, the current density reaches 42 mA/cm~2 when the applied field is 3.72 V/μm. These experimental results unambiguously confirm Binh's theoretical analysis (Birth et al. Phys Rev Lett, 2000, 85(4): 864-867) that the FE performance would be prominently enhanced with the coating of an ultra-thin wide band-gap semiconductor film.

  4. Pulsed-laser-deposited YBCO thin films using modified MTG processed targets

    CERN Document Server

    Kim, C H; Kim, I T; Hahn, T S

    1999-01-01

    YBCO thin films were deposited by pulsed laser deposition from targets fabricated using the modified melt-textured growth (MTG) method and the solid-state sintering (SSS) method. All of the films showed c-axis orientations, but the films from the MTG targets had better crystallinity than those from the SSS targets. As the substrate temperature was increased, T sub c and J sub c of the films increased. The films from the MTG targets showed better superconducting properties than those from the SSS targets. From the composition analysis of the targets, the Y-richer vapor species arriving at the substrate from the MTG targets are thought to form a thermodynamically more stable YBCO phase with less cation disorder.

  5. Multilayer zone plates for X-ray focusing fabricated by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Doering, Florian; Eberl, Christian; Liese, Tobias; Krebs, Hans-Ulrich [Institut fuer Materialphysik, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

    2012-07-01

    X-ray microscopy in the soft and hard regime is a highly useful technique for biological and materials sciences, polymer research, colloidal science and even earth science. One alternative approach for two-dimensional x-ray focusing is to prepare non-periodic multilayer structures. They can be designed in zone plate geometry by depositing high quality non-periodic multilayers on wires according to the Fresnel zone plate law. For this, ZrO{sub 2}/Ti and W/Si multilayers with high optical contrast in the soft and hard x-ray region, respectively, were pulsed laser deposited (PLD) at 248 nm. In this contribution, the growth of multilayers on flat and curved surfaces (studied by electron microscopy after focused ion beam preparation) is compared, and the fabrication steps of different zone plate structures are presented.

  6. Structural and morphological properties of metallic thin films grown by pulsed laser deposition for photocathode application

    Science.gov (United States)

    Lorusso, A.; Gontad, F.; Caricato, A. P.; Chiadroni, E.; Broitman, E.; Perrone, A.

    2016-03-01

    In this work yttrium and lead thin films have been deposited by pulsed laser deposition technique and characterized by ex situ different diagnostic methods. All the films were adherent to the substrates and revealed a polycrystalline structure. Y films were uniform with a very low roughness and droplet density, while Pb thin films were characterized by a grain morphology with a relatively high roughness and droplet density. Such metallic materials are studied because they are proposed as a good alternative to copper and niobium photocathodes which are generally used in radiofrequency and superconducting radiofrequency guns, respectively. The photoemission performances of the photocathodes based on Y and Pb thin films have been also studied and discussed.

  7. On the wetting behavior of ceria thin films grown by pulsed laser deposition

    Science.gov (United States)

    Fu, Sin-Pui; Rossero, Jorge; Chen, Chen; Li, Daniel; Takoudis, Christos G.; Abiade, Jeremiah T.

    2017-02-01

    Polymers are most widely used in the production of water-repellant coatings. However, their use in applications requiring wear resistance or high-temperature stability is extremely limited. A recent report suggests that wear resistant, thermally stable rare earth oxide materials like cerium dioxide (ceria) are intrinsically water repellant. We have studied this intriguing finding for ceria thin films fabricated by pulsed laser deposition (PLD) at different oxygen pressures and different substrate temperatures. We used a custom apparatus for measuring water contact angles on ceria films deposited by PLD. X-ray photoelectron spectroscopy was used to determine the relationship between the ceria wetting behavior and ceria surface chemistry. Our results show that ceria thin films are intrinsically hydrophilic and that hydrophobicity arises due to adsorption of hydrocarbon species after ˜24 h.

  8. Nanostructured rhodium films produced by pulsed laser deposition for nuclear fusion applications

    Science.gov (United States)

    Passoni, M.; Dellasega, D.; Grosso, G.; Conti, C.; Ubaldi, M. C.; Bottani, C. E.

    2010-09-01

    In this paper the possibilities offered by pulsed laser deposition (PLD) for the production of nanostructured rhodium films with improved properties are explored. Thanks to its high reflectivity and low sputtering yield, rhodium is one of the best candidates for the development of thin films to be used in first mirrors, which are crucial components in many diagnostic systems of thermonuclear magnetic fusion machines, like tokamaks. Due to the features of PLD, by varying the process parameters it is possible to tailor both the structure, i.e. the nanocrystalline domain size of the deposited films, down to less than 5 nm and separately control the other relevant physical properties. This leads to modifications in growth regime and annealing dynamics, in such a way that both morphology and reflectivity achieve the properties demanded to use these films as mirrors for fusion applications, opening at the same time new possibilities for the future improvement of thermo-mechanical and adhesion properties.

  9. Fatigue mechanism of yttrium-doped hafnium oxide ferroelectric thin films fabricated by pulsed laser deposition.

    Science.gov (United States)

    Huang, Fei; Chen, Xing; Liang, Xiao; Qin, Jun; Zhang, Yan; Huang, Taixing; Wang, Zhuo; Peng, Bo; Zhou, Peiheng; Lu, Haipeng; Zhang, Li; Deng, Longjiang; Liu, Ming; Liu, Qi; Tian, He; Bi, Lei

    2017-02-01

    Owing to their prominent stability and CMOS compatibility, HfO2-based ferroelectric films have attracted great attention as promising candidates for ferroelectric random-access memory applications. A major reliability issue for HfO2 based ferroelectric devices is fatigue. So far, there have been a few studies on the fatigue mechanism of this material. Here, we report a systematic study of the fatigue mechanism of yttrium-doped hafnium oxide (HYO) ferroelectric thin films deposited by pulsed laser deposition. The influence of pulse width, pulse amplitude and temperature on the fatigue behavior of HYO during field cycling is studied. The temperature dependent conduction mechanism is characterized after different fatigue cycles. Domain wall pinning caused by carrier injection at shallow defect centers is found to be the major fatigue mechanism of this material. The fatigued device can fully recover to the fatigue-free state after being heated at 90 °C for 30 min, confirming the shallow trap characteristic of the domain wall pinning defects.

  10. Note: Large area deposition of Rh single and Rh/W/Cu multilayer thin films on stainless steel substrate by pulsed laser deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Mostako, A. T. T.; Khare, Alika, E-mail: alika@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India)

    2014-04-15

    Mirror like thin films of single layer Rh and multilayer Rh/W/Cu are deposited on highly polished 50 mm diameter stainless steel substrate by Pulsed Laser Deposition (PLD) technique for first mirror application in fusion reactors. For this, the conventional PLD technique has been modified by incorporating substrate rastering stage for large area deposition via PLD. Process optimization to achieve uniformity of deposition as estimated from fringe visibility and thickness is also discussed.

  11. Fabrication of Nb/Pb structures through ultrashort pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gontad, Francisco; Lorusso, Antonella, E-mail: antonella.lorusso@le.infn.it; Perrone, Alessio [Dipartimento di Matematica e Fisica “E. De Giorgi,” Università del Salento and Istituto Nazionale di Fisica Nucleare, 73100 Lecce (Italy); Klini, Argyro; Fotakis, Costas [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), 100 N. Plastira St., GR 70013 Heraklion, Crete (Greece); Broitman, Esteban [Thin Film Physics Division, IFM, Linköping University, 581-83 Linköping (Sweden)

    2016-07-15

    This work reports the fabrication of Nb/Pb structures with an application as photocathode devices. The use of relatively low energy densities for the ablation of Nb with ultrashort pulses favors the reduction of droplets during the growth of the film. However, the use of laser fluences in this ablation regime results in a consequent reduction in the average deposition rate. On the other hand, despite the low deposition rate, the films present a superior adherence to the substrate and an excellent coverage of the irregular substrate surface, avoiding the appearance of voids or discontinuities on the film surface. Moreover, the low energy densities used for the ablation favor the growth of nanocrystalline films with a similar crystalline structure to the bulk material. Therefore, the use of low ablation energy densities with ultrashort pulses for the deposition of the Nb thin films allows the growth of very adherent and nanocrystalline films with adequate properties for the fabrication of Nb/Pb structures to be included in superconducting radiofrequency cavities.

  12. Formation of copper tin sulfide films by pulsed laser deposition at 248 and 355 nm

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt; Crovetto, Andrea; Canulescu, Stela;

    2016-01-01

    The influence of the laser wavelength on the deposition of copper tin sulfide (CTS) and SnS-rich CTS with a 248-nm KrF excimer laser (pulse length τ = 20 ns) and a 355-nm frequency-tripled Nd:YAG laser (τ = 6 ns) was investigated. A comparative study of the two UV wavelengths shows that the CTS...

  13. Formation of copper tin sulfide films by pulsed laser deposition at 248 and 355 nm

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt; Crovetto, Andrea; Canulescu, Stela

    2016-01-01

    The influence of the laser wavelength on the deposition of copper tin sulfide (CTS) and SnS-rich CTS with a 248-nm KrF excimer laser (pulse length τ = 20 ns) and a 355-nm frequency-tripled Nd:YAG laser (τ = 6 ns) was investigated. A comparative study of the two UV wavelengths shows that the CTS...

  14. Structural and Optical Properties of Eu Doped ZnO Nanorods prepared by Pulsed Laser Deposition

    KAUST Repository

    Alarawi, Abeer

    2014-06-23

    Nano structured wide band gap semiconductors have attracted attention of many researchers due to their potential electronic and optoelectronic applications. In this thesis, we report successful synthesis of well aligned Eu doped ZnO nano-rods prepared, for the first time to our knowledge, by pulsed laser deposition (PLD) without any catalyst. X-ray diffraction (XRD) patterns shows that these Eu doped ZnO nanorods are grown along the c-axis of ZnO wurtzite structure. We have studied the effect of the PLD growth conditions on forming vertically aligned Eu doped ZnO nanorods. The structural properties of the material are investigated using a -scanning electron microscope (SEM). The PLD parameters must be carefully controlled in order to obtain c-axis oriented ZnO nanorods on sapphire substrates, without the use of any catalyst. The experiments conducted in order to identify the optimal growth conditions confirmed that, by adjusting the target-substrate distance, substrate temperature, laser energy and deposition duration, the nanorod size could be successfully controlled. Most importantly, the results indicated that the photoluminescence (PL) properties reflect the quality of the ZnO nanorods. These parameters can change the material’s structure from one-dimensional to two-dimensional however the laser energy and frequency affect the size and the height of the nanorods; the xygen pressure changes the density of the nanorods.

  15. Highly sensitive NO2 sensors by pulsed laser deposition on graphene

    Science.gov (United States)

    Kodu, Margus; Berholts, Artjom; Kahro, Tauno; Avarmaa, Tea; Kasikov, Aarne; Niilisk, Ahti; Alles, Harry; Jaaniso, Raivo

    2016-09-01

    Graphene as a single-atomic-layer material is fully exposed to environmental factors and has therefore a great potential for the creation of sensitive gas sensors. However, in order to realize this potential for different polluting gases, graphene has to be functionalized—adsorption centers of different types and with high affinity to target gases have to be created at its surface. In the present work, the modification of graphene by small amounts of laser-ablated materials is introduced for this purpose as a versatile and precise tool. The approach has been demonstrated with two very different materials chosen for pulsed laser deposition (PLD)—a metal (Ag) and a dielectric oxide (ZrO2). It was shown that the gas response and its recovery rate can be significantly enhanced by choosing the PLD target material and deposition conditions. The response to NO2 gas in air was amplified up to 40 times in the case of PLD-modified graphene, in comparison with pristine graphene, and it reached 7%-8% at 40 ppb of NO2 and 20%-30% at 1 ppm of NO2. The PLD process was conducted in a background gas (5 × 10-2 mbar oxygen or nitrogen) and resulted in the atomic areal densities of the deposited materials of about 1015 cm-2. The ultimate level of NO2 detection in air, as extrapolated from the experimental data obtained at room temperature under mild ultraviolet excitation, was below 1 ppb.

  16. Room temperature growth of biaxially aligned yttria-stabilized zirconia films on glass substrates by pulsed-laser deposition

    CERN Document Server

    Li Peng; Mazumder, J

    2003-01-01

    Room temperature deposition of biaxially textured yttria-stabilized zirconia (YSZ) films on amorphous glass substrates was successfully achieved by conventional pulsed-laser deposition. The influence of the surrounding gases, their pressure and the deposition time on the structure of the films was studied. A columnar growth process was revealed based on the experimental results. The grown biaxial texture appears as a kind of substrate independence, which makes it possible to fabricate in-plane aligned YSZ films on various substrates.

  17. Superconducting MgB2 Thin Films with Tc ≈ 39 K Grown by Pulsed Laser Deposition

    Institute of Scientific and Technical Information of China (English)

    王淑芳; 戴守愚; 周岳亮; 陈正豪; 崔大复; 许佳迪; 何萌; 吕惠宾; 杨国桢

    2001-01-01

    Superconducting MgB2 thin films were fabricated on Al2 O3 (0001) substrates under ex situ processing conditions.Boron thin films were deposited by pulsed laser deposition followed by a post-annealing process. Resistance measurements of the deposited MgB2 films show Tc of ~39 K, while scanning electron microscopy and x-ray vdiffraction analysis indicate that the films consist of well-crystallized grains with a highly c-axis-oriented structure.

  18. Ultrafast Pulsed-Laser Applications for Semiconductor Thin Film Deposition and Graphite Photoexfoliation

    Science.gov (United States)

    Oraiqat, Ibrahim Malek

    This thesis focuses on the application of ultrafast lasers in nanomaterial synthesis. Two techniques are investigated: Ultrafast Pulsed Laser Deposition (UFPLD) of semiconductor nanoparticle thin films and ultrafast laser scanning for the photoexfoliation of graphite to synthesize graphene. The importance of the work is its demonstration that the process of making nanoparticles with ultrafast lasers is extremely versatile and can be applied to practically any material and substrate. Moreover, the process is scalable to large areas: by scanning the laser with appropriate optics it is possible to coat square meters of materials (e.g., battery electrodes) quickly and inexpensively with nanoparticles. With UFPLD we have shown there is a nanoparticle size dependence on the laser fluence and the optical emission spectrum of the plume can be used to determine a fluence that favors smaller nanoparticles, in the range of 10-20 nm diameter and 3-5 nm in height. We have also demonstrated there are two structural types of particles: amorphous and crystalline, as verified with XRD and Raman spectroscopy. When deposited as a coating, the nanoparticles can behave as a quasi-continuous thin film with very promising carrier mobilities, 5-52 cm2/Vs, substantially higher than for other spray-coated thin film technologies and orders of magnitude larger than those of colloidal quantum dot (QD) films. Scanning an ultrafast laser over the surface of graphite was shown to produce both filamentary structures and sheets which are semi-transparent to the secondary-electron beam in SEM. These sheets resemble layers of graphene produced by exfoliation. An ultrafast laser "printing" configuration was also identified by coating a thin, transparent substrate with graphite particles and irradiating the back of the film for a forward transfer of material onto a receiving substrate. A promising application of laser-irradiated graphene coatings was investigated, namely to improve the charge

  19. Experimental study of direct laser deposition of Ti-6Al-4V and Inconel 718 by using pulsed parameters.

    Science.gov (United States)

    Shah, Kamran; Izhar Ul Haq; Shah, Shaukat Ali; Khan, Farid Ullah; Khan, Muhammad Tahir; Khan, Sikander

    2014-01-01

    Laser direct metal deposition (LDMD) has developed from a prototyping to a single metal manufacturing tool. Its potential for creating multimaterial and functionally graded structures is now beginning to be explored. This work is a first part of a study in which a single layer of Inconel 718 is deposited on Ti-6Al-4V substrate. Single layer tracks were built at a range of powder mass flow rates using a coaxial nozzle and 1.5 kW diode laser operating in both continuous and pulsed beam modes. This part of the study focused on the experimental findings during the deposition of Inconel 718 powder on Ti-6Al-4V substrate. Scanning electron microscopy (SEM) and X-ray diffraction analysis were performed for characterization and phase identification. Residual stress measurement had been carried out to ascertain the effects of laser pulse parameters on the crack development during the deposition process.

  20. Experimental Study of Direct Laser Deposition of Ti-6Al-4V and Inconel 718 by Using Pulsed Parameters

    Directory of Open Access Journals (Sweden)

    Kamran Shah

    2014-01-01

    Full Text Available Laser direct metal deposition (LDMD has developed from a prototyping to a single metal manufacturing tool. Its potential for creating multimaterial and functionally graded structures is now beginning to be explored. This work is a first part of a study in which a single layer of Inconel 718 is deposited on Ti-6Al-4V substrate. Single layer tracks were built at a range of powder mass flow rates using a coaxial nozzle and 1.5 kW diode laser operating in both continuous and pulsed beam modes. This part of the study focused on the experimental findings during the deposition of Inconel 718 powder on Ti-6Al-4V substrate. Scanning electron microscopy (SEM and X-ray diffraction analysis were performed for characterization and phase identification. Residual stress measurement had been carried out to ascertain the effects of laser pulse parameters on the crack development during the deposition process.

  1. Optical properties of PMN-PT thin films prepared using pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tong, X.L., E-mail: tongxinglin@yahoo.com.cn [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Ministry of Education, 122 Luoshi Road, Wuhan 430070 (China); Lin, K.; Lv, D.J.; Yang, M.H.; Liu, Z.X.; Zhang, D.S. [Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Wuhan University of Technology, Ministry of Education, 122 Luoshi Road, Wuhan 430070 (China)

    2009-06-30

    (1 - x)Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-xPbTiO{sub 3} (PMN-PT) thin films have been deposited on quartz substrates using pulsed laser deposition (PLD). Crystalline microstructure of the deposited PMN-PT thin films has been investigated with X-ray diffraction (XRD). Optical transmission spectroscopy and Raman spectroscopy are used to characterize optical properties of the deposited PMN-PT thin films. The results show that the PMN-PT thin films of perovskite structure have been formed, and the crystalline and optical properties of the PMN-PT thin films can be improved as increasing the annealing temperature to 750 deg. C, but further increasing the annealing temperature to 950 deg. C may lead to a degradation of the crystallinity and the optical properties of the PMN-PT thin films. In addition, a weak second harmonic intensity (SHG) has been observed for the PMN-PT thin film formed at the optimum annealing temperature of 750 deg. C according to Maker fringe method. All these suggest that the annealing temperature has significant effect on the structural and optical properties of the PMN-PT thin films.

  2. Study on pulsed laser ablation and deposition of ZnO thin films by L-MBE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    ZnO,as a wide-band gap semiconductor,has recently become a new research fo-cus in the field of ultraviolet optoelectronic semiconductors. Laser molecular beam epitaxy(L-MBE) is quite useful for the unit cell layer-by-layer epitaxial growth of zinc oxide thin films from the sintered ceramic target. The ZnO ceramic target with high purity was ablated by KrF laser pulses in an ultra high vacuum to deposit ZnO thin film during the process of L-MBE. It is found that the deposition rate of ZnO thin film by L-MBE is much lower than that by conventional pulsed laser deposition(PLD) . Based on the experimental phenomena in the ZnO thin film growth process and the thermal-controlling mechanism of the nanosecond(ns) pulsed laser abla-tion of ZnO ceramic target,the suggested effective ablating time during the pulse duration can explain the very low deposition rate of the ZnO film by L-MBE. The unique dynamic mechanism for growing ZnO thin film is analyzed. Both the high energy of the deposition species and the low growth rate of the film are really beneficial for the L-MBE growth of the ZnO thin film with high crystallinity at low temperature.

  3. Visible light-harvesting of TiO{sub 2} nanotubes array by pulsed laser deposited CdS

    Energy Technology Data Exchange (ETDEWEB)

    Bjelajac, Andjelika, E-mail: abjelajac@tmf.bg.ac.rs [Innovation Center of Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade (Serbia); Djokic, Veljko; Petrovic, Rada [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade (Serbia); Socol, Gabiel; Mihailescu, Ion N. [National Institute for Lasers, Plasma, and Radiation Physics, Lasers Department, “Laser-Surface-Plasma Interactions” Laboratory, PO Box MG-54, RO-77125 Magurele, Ilfov (Romania); Florea, Ileana; Ersen, Ovidiu [Institut de Physique et Chimie des Materiaux de Strasbourg, CNRS – Université de Strasbourg (UDS) UMR 7504, 23, rue du Loess, BP 43, 67037 Strasbourg Cedex 02 (France); Janackovic, Djordje [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade (Serbia)

    2014-08-01

    Titanium dioxide (TiO{sub 2}) nanotubes arrays, obtained by anodization technique and annealing, were decorated with CdS using pulsed laser deposition method. Their structural, morphological and chemical characterization was carried out by electron microscopy in scanning (SEM) and transmission (TEM) modes, combined with energy dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS). It was demonstrated that the quantity of deposited CdS can be controlled by varying the number of laser pulses. The chemical mapping of the elements of interest was performed using the energy filtered mode of the electron microscope. The results showed that pulse laser deposition is an adequate technique for deposition of CdS inside and between 100 nm wide TiO{sub 2} nanotubes. The diffuse reflectance spectroscopy investigation of selected samples proved that the absorption edge of the prepared CdS/TiO{sub 2} nanocomposites is significantly extended to the visible range. The corresponding band gaps were determinated from the Tauc plot of transformed Kubelka–Munk function. The band gap reduction of TiO{sub 2} nanotubes by pulsed laser deposition of CdS was put in evidence.

  4. Study on pulsed laser ablation and deposition of ZnO thin films by L-MBE

    Institute of Scientific and Technical Information of China (English)

    HE YongNing; ZHANG JingWen; YANG XiaoDong; XU QingAn; ZHU ChangChun; HOU Xun

    2007-01-01

    ZnO, as a wide-band gap semiconductor, has recently become a new research focus in the field of ultraviolet optoelectronic semiconductors. Laser molecular beam epitaxy (L-MBE) is quite useful for the unit cell layer-by-layer epitaxial growth of zinc oxide thin films from the sintered ceramic target. The ZnO ceramic target with high purity was ablated by KrF laser pulses in an ultra high vacuum to deposit ZnO thin film during the process of L-MBE. It is found that the deposition rate of ZnO thin film by L-MBE is much lower than that by conventional pulsed laser deposition (PLD). Based on the experimental phenomena in the ZnO thin film growth process and the thermal-controlling mechanism of the nanosecond (ns) pulsed laser ablation of ZnO ceramic target, the suggested effective ablating time during the pulse duration can explain the very low deposition rate of the ZnO film by L-MBE. The unique dynamic mechanism for growing ZnO thin film is analyzed. Both the high energy of the deposition species and the low growth rate of the film are really beneficial for the L-MBE growth of the ZnO thin film with high crystallinity at low temperature.

  5. Yttria and ceria doped zirconia thin films grown by pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    F. Saporiti

    2013-06-01

    Full Text Available The Yttria stabilized Zirconia (YSZ is a standard electrolyte for solid oxide fuel cells (SOFCs, which are potential candidates for next generation portable and mobile power sources. YSZ electrolyte thin films having a cubic single phase allow reducing the SOFC operating temperature without diminishing the electrochemical power density. Films of 8 mol% Yttria stabilized Zirconia (8YSZ and films with addition of 4 weight% Ceria (8YSZ + 4CeO2 were grown by pulsed laser deposition (PLD technique using 8YSZ and 8YSZ + 4CeO2 targets and a Nd-YAG laser (355 nm. Films have been deposited on Soda-Calcia-Silica glass and Si(100 substrates at room temperature. The morphology and structural characteristics of the samples have been studied by means of X-ray diffraction and scanning electron microscopy. Films of a cubic-YSZ single phase with thickness in the range of 1-3 µm were grown on different substrates.

  6. Yttria and ceria doped zirconia thin films grown by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Saporiti, F.; Juarez, R. E., E-mail: cididi@fi.uba.ar [Grupo de Materiales Avanzados, Facultad de Ingenieria, Universidad de Buenos Aires (Argentina); Audebert, F. [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Boudard, M. [Laboratoire des Materiaux et du Genie Physique (CNRS), Grenoble (France)

    2013-11-01

    The Yttria stabilized Zirconia (YSZ) is a standard electrolyte for solid oxide fuel cells (SOFCs), which are potential candidates for next generation portable and mobile power sources. YSZ electrolyte thin films having a cubic single phase allow reducing the SOFC operating temperature without diminishing the electrochemical power density. Films of 8 mol% Yttria stabilized Zirconia (8YSZ) and films with addition of 4 weight% Ceria (8YSZ + 4CeO{sub 2}) were grown by pulsed laser deposition (PLD) technique using 8YSZ and 8YSZ + 4CeO{sub 2} targets and a Nd-YAG laser (355 nm). Films have been deposited on Soda-Calcia-Silica glass and Si(100) substrates at room temperature. The morphology and structural characteristics of the samples have been studied by means of X-ray diffraction and scanning electron microscopy. Films of a cubic-YSZ single phase with thickness in the range of 1-3 Micro-Sign m were grown on different substrates (author)

  7. Structural and electrical properties of tantalum oxide films grown by photo-assisted pulsed laser deposition

    Science.gov (United States)

    Zhang, Jun-Ying; Boyd, Ian W.

    2002-01-01

    We describe the growth of thin films of Ta 2O 5 on quartz and silicon (1 0 0) substrates by an in situ photo-assisted pulsed laser deposition (photo-PLD) using radiation from a Nd:YAG laser (wavelength, λ=532 nm) to stimulate the ablation, and from an excimer lamp to excite additional photochemistry. The layers grown were investigated by Fourier transform infrared (FT-IR) spectroscopy, UV spectrophotometry, atomic force microscopy (AFM), ellipsometry and electrical measurements. We have found that they exhibit a significant improvement in microstructure, and optical and electrical properties compared with conventional PLD films prepared under, otherwise, identical conditions. For example, FT-IR results showed that the suboxide content in the as-grown films deposited by the photo-PLD process is less, while the leakage current density was an order of magnitude less at around 10 -6 A/cm 2 at a bias of 1 V. These results indicate that this photo-PLD process approach can be advantageous for dielectric and optical oxide film growth.

  8. Pulsed laser deposition of hydroxyapatite on nanostructured titanium towards drug eluting implants.

    Science.gov (United States)

    Rajesh P; Mohan, Nimmy; Yokogawa, Y; Varma, Harikrishna

    2013-07-01

    Titania nanotubes grown on titanium substrates by electrochemical anodization in glycerol-ammonium fluoride-water system were used to develop efficient drug carrying implants upon coating hydroxyapatite (HA) ceramic. The nanostructured surfaces achieved by anodization were caped with HA crystallites by pulsed laser deposition. The implant substrates were studied for their drug carrying capacity using gentamicin as a model. The nano-tubular surface with HA coating had better drug loading capacity of about 800 μg/cm(2) gentamicin while the bare anodized substrate carried less than 660 μg/cm(2). The HA coating alone stored as low as 68 μg/cm(2) and released the drug within the initial burst period itself. The ceramic coated anodized substrates were found to be more efficient in controlled delivery for longer than 160 h with a drug release of 0.5 μg/cm(2) even towards the end. The substrate with nanostructuring alone delivered the whole drug within 140 h. This study proposes the application of laser deposition of HA over nanostructured titanium, which proves to be promising towards controlled drug eluting bioceramic coated metallic prostheses.

  9. Preparation of BiFeO3 thin films by pulsed laser deposition method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guan-jun; CHENG Jin-rong; CHEN Rui; YU Sheng-wen; MENG Zhong-yan

    2006-01-01

    BiFeO3 (BFO) thin films were prepared on Pt(111)/TiO2/SiO2/Si(100) substrates by the pulsed-laser deposition (PLD) technique at a low temperature of 450℃. The XRD results indicate that the BFO thin films are of perovskite structure with the presence of small amount of second phases. The oxygen pressures have great effect on the crystalline structures and dielectric properties of BFO thin films. The dielectric constant of the BFO thin films decreases with increasing oxygen pressures,achieving 186,171 and 160 at the frequency of 104 Hz for the oxygen pressures of 0.666,1.333 and 13.332 Pa,respectively. The BFO thin films prepared at the oxygen pressure of 0.666 Pa reveal a saturated hysteresis loop with the remanent polarization of 7.5 μC/cm2 and the coercive field of 176 kV/cm.

  10. Manifestation of unusual size effects in granular thin films prepared by pulsed laser deposition

    Science.gov (United States)

    Sergeenkov, S.; Cichetto, L.; Diaz, J. C. C. A.; Bastos, W. B.; Longo, E.; Araújo-Moreira, F. M.

    2016-11-01

    We demonstrate manifestation of some rather unusual size effects in granular thin films prepared by a pulsed laser deposition technique. We observed that the temperature dependence of resistivity ρ(T) notably depends on the relation between the grain size Rg and the film thickness d. Namely, more granular LaNiO3 thin films (with small values of Rg) grown on LaAlO3 substrate are found to follow a universal ρ(T) ∝T 3 / 2 law for all the measured temperatures. While less granular thin films (with larger values of Rg), exhibit a more complicated behavior accompanied by a clear-cut crossover (around Tcr = 200 K), from ρ(T) ∝T 3 / 2 (for 20 K temperature size effects (when an average grain size Rg becomes comparable with the thermal de Broglie wavelength Λ) leading to the crossover temperature Tcr ∝(d /Rg) 2 .

  11. Self-catalyst synthesis of aligned ZnO nanorods by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    LEN; Song-En; Andy

    2009-01-01

    High-density well-aligned ZnO nanorods were successfully synthesized on ZnO-buffer-layer coated indium phosphide (InP) (100) substrates by a pulsed laser deposition (PLD) method. Scanning electron microscopy images show that the ZnO buffer layer formed uniform drip-like structure and ZnO nano- rods were well-oriented perpendicular to the substrate surface. The sharp diffraction peak observed at 34.46° in X-ray diffraction scanning pattern suggests that the ZnO nanorods exhibit a (002)-preferred orientation. The PL spectra of ZnO samples shows a strong near band edge emission centered at about 380 nm and a weak deep level emission centered at around 495 nm, and it demonstrates that the ZnO nanorods produced in this work have high optical quality, which sheds light on further applications for nanodevices.

  12. Lithium outdiffusion in LiTi2O4 thin films grown by pulsed laser deposition

    Science.gov (United States)

    Mesoraca, S.; Kleibeuker, J. E.; Prasad, B.; MacManus-Driscoll, J. L.; Blamire, M. G.

    2016-11-01

    We report surface chemical cation composition analysis of high quality superconducting LiTi2O4 thin films, grown epitaxially on MgAl2O4 (111) substrates by pulsed laser deposition. The superconducting transition temperature of the films was 13.8 K. Surface chemical composition is crucial for the formation of a good metal/insulator interface for integrating LiTi2O4 into full-oxide spin-filtering devices in order to minimize the formation of structural defects and increase the spin polarisation efficiency. In consideration of this, we report a detailed angle resolved x-ray photoelectron spectroscopy analysis. Results show Li segregation at the surface of LiTi2O4 films. We attribute this process due to outdiffusion of Li toward the outermost LiTi2O4 layers.

  13. Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition

    Science.gov (United States)

    Liang, Yangang; Yao, Yangyi; Zhang, Xiaohang; Hsu, Wei-Lun; Gong, Yunhui; Shin, Jongmoon; Wachsman, Eric D.; Dagenais, Mario; Takeuchi, Ichiro

    2016-01-01

    We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD) of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH3NH3PbI3 thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.

  14. Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yangang; Zhang, Xiaohang; Gong, Yunhui; Shin, Jongmoon; Wachsman, Eric D.; Takeuchi, Ichiro, E-mail: takeuchi@umd.edu [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740 (United States); Yao, Yangyi; Hsu, Wei-Lun; Dagenais, Mario [Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20740 (United States)

    2016-01-15

    We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD) of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH{sub 3}NH{sub 3}PbI{sub 3} thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.

  15. Fabrication of organic-inorganic perovskite thin films for planar solar cells via pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    Yangang Liang

    2016-01-01

    Full Text Available We report on fabrication of organic-inorganic perovskite thin films using a hybrid method consisting of pulsed laser deposition (PLD of lead iodide and spin-coating of methylammonium iodide. Smooth and highly crystalline CH3NH3PbI3 thin films have been fabricated on silicon and glass coated substrates with fluorine doped tin oxide using this PLD-based hybrid method. Planar perovskite solar cells with an inverted structure have been successfully fabricated using the perovskite films. Because of its versatility, the PLD-based hybrid fabrication method not only provides an easy and precise control of the thickness of the perovskite thin films, but also offers a straightforward platform for studying the potential feasibility in using other metal halides and organic salts for formation of the organic-inorganic perovskite structure.

  16. Pulsed Laser Deposited Nickel Doped Zinc Oxide Thin Films: Structural and Optical Investigations

    Directory of Open Access Journals (Sweden)

    Tanveer A. Dar

    2013-05-01

    Full Text Available Structural and optical studies has been done on Nickel doped Zinc Oxide (NixZn1 – xO, x  0.03, 0.05 and 0.07 by weight thin films prepared by pulsed laser deposition technique. The films are characterized by X-ray diffraction, Uv-vis spectroscopy, X-ray photoelectron spectroscopy. We observed a slight red shift in the optical band gap in the NiZnO subsequent to Ni doping. This shift can be assigned due to the sp-d exchange interaction of Ni- d states with s and p-states of ZnO. Also X-ray photoelectron spectroscopy studies show that Ni has well substituted in + 2 oxidation state by replacing Zn2+.

  17. Enhanced photoluminescence and heterojunction characteristics of pulsed laser deposited ZnO nanostructures

    Science.gov (United States)

    Mannam, Ramanjaneyulu; Kumar, E. Senthil; Priyadarshini, D. M.; Bellarmine, F.; DasGupta, Nandita; Ramachandra Rao, M. S.

    2017-10-01

    We report on the growth of ZnO nanostructures in different gas ambient (Ar and N2) using pulsed laser deposition technique. Despite the similar growth temperature, use of N2 ambient gas resulted in well-aligned nanorods with flat surface at the tip, whereas, nanorods grown with Ar ambient exhibited tapered tips. The Nanorods grown under N2 ambient exhibited additional Raman modes corresponding to N induced zinc interstitials. The nanorods are c-axis oriented and highly epitaxial in nature. Photoluminescence spectroscopy reveals that the UV emission can be significantly enhanced by 10 times for the nanorods grown under Ar ambient. The enhanced UV emission is attributed to the reduction in polarization electric field along the c-axis. n-ZnO nanorods/p-Si heterojunction showed rectifying I-V characteristics with a turn of voltage of 3.4 V.

  18. Pulsed laser deposited LaInO{sub 3} thin films and their photoluminescence characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Chaluvadi, Sandeep Kumar [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Centre for Nanotechnology Research, SENSE, VIT University, Vellore, Tamil Nadu 632014 (India); Aswin, V.; Kumar, Pramod; Singh, Pooja; Haranath, D.; Rout, P.K. [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Dogra, Anjana, E-mail: anjanad@nplindia.org [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India)

    2015-10-15

    Photoluminescence studies of pulsed laser deposition grown LaInO{sub 3} thin films on TiO{sub 2} terminated SrTiO{sub 3} substrate showed a broad-band blue emission peaking at 412 nm, which is primarily attributed to the charge transfer transitions between oxygen and indium, inter (d–f) and intra (f–f) band transitions. The results are analysed based on the mechanism of absorption and emission within the d{sup 10} levels of In{sup 3+} ions. Broadening of the photoluminescence emission is observed with reduction in size of the crystallite owing to quantum confinement effects. - Highlights: • First time grown thin films of LaInO{sub 3} by PLD. • Interesting new photoluminescence features in thin films of LaInO{sub 3}. • Results are discussed on the basis of quantum confinement.

  19. Preparation and tribological properties of DLC/Ti film by pulsed laser arc deposition

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhen-Yu; Lu Xin-Chun; Luo Jian-Bin; Shao Tian-Min; Qing Tao; Zhang Chen-Hui

    2006-01-01

    This paper reports that DLC (diamond like carbon)/Ti and DLC films were prepared by using pulsed laser arc deposition. R-ray diffraction, Auger electron spectroscopy, Raman spectroscopy, atomic force microscopy, nanoindenter, spectroscopic ellipsometer, surface profiler and micro-tribometer were employed to study the structure and tribological properties of DLC/Ti and DLC films. The results show that DLC/Ti film, with I(D)/I(G) 0.28 and corresponding to 76% sp3 content calculated by Raman spectroscopy, uniform chemical composition along depth direction, 98 at% content of carbon, hardness 8.2 GPa and Young's modulus 110.5 GPa, compressive stress 6.579 GPa, thickness 46 nm,coefficient of friction 0.08, and critical load 95mN, exhibits excellent mechanical and tribological properties.

  20. How to obtain a magnetic hard-soft architecture by pulsed laser deposition.

    Science.gov (United States)

    Fix, T; Trassin, M; Hassan, R Sayed; Schmerber, G; Viart, N; Mény, C; Colis, S; Dinia, A

    2007-12-12

    In spin valve type systems, one ferromagnetic electrode must be magnetically hard to act as a reference layer while the other electrode must be magnetically soft to act as a sensor or storage layer. This magnetic hard-soft architecture can usually be obtained by four different methods: the use of two ferromagnets with different coercive fields (here CoFe(2) and Ni(80)Fe(20)), the use of an underlayer enhancing the coercive field of one of the two ferromagnets (here Ta and Ru), the use of a ferromagnet coupled to a ferrimagnet or antiferromagnet (here NiO/CoFe(2) and CoFe(2)O(4)/CoFe(2)), or the use of an artificial antiferromagnet (here CoFe(2)/Ru/CoFe(2)). We show that at least the first and the third methods seem to work with pulsed laser deposition in the thermodynamic conditions used.

  1. Pulsed laser deposition of air-sensitive hydride epitaxial thin films: LiH

    Energy Technology Data Exchange (ETDEWEB)

    Oguchi, Hiroyuki, E-mail: oguchi@nanosys.mech.tohoku.ac.jp [Department of Nanomechanics, Tohoku University, Sendai 980-8579 (Japan); Micro System Integration Center (muSIC), Tohoku University, Sendai 980-0845 (Japan); Isobe, Shigehito [Creative Research Institution, Hokkaido University, Sapporo 001-0021 (Japan); Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Kuwano, Hiroki [Department of Nanomechanics, Tohoku University, Sendai 980-8579 (Japan); Shiraki, Susumu; Hitosugi, Taro [Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai 980-8577 (Japan); Orimo, Shin-ichi [Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2015-09-01

    We report on the epitaxial thin film growth of an air-sensitive hydride, lithium hydride (LiH), using pulsed laser deposition (PLD). We first synthesized a dense LiH target, which is key for PLD growth of high-quality hydride films. Then, we obtained epitaxial thin films of [100]-oriented LiH on a MgO(100) substrate at 250 °C under a hydrogen pressure of 1.3 × 10{sup −2} Pa. Atomic force microscopy revealed that the film demonstrates a Stranski-Krastanov growth mode and that the film with a thickness of ∼10 nm has a good surface flatness, with root-mean-square roughness R{sub RMS} of ∼0.4 nm.

  2. Electrical characterization of gadolinia doped ceria films grown by pulsed laser deposition

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Heiroth, Sebastian; Lundberg, Mats

    2010-01-01

    Electrical characterization of 10 mol% gadolinia doped ceria (CGO10) films of different thicknesses prepared on MgO(100) substrates by pulsed laser deposition is presented. Dense, polycrystalline and textured films characterized by fine grains (grain sizes ... thickness. The conductivity of the nanocrystalline films is lower (7.0×10−4 S/cm for the 20-nm film and 3.6×10−3 S/cm for the 435-nm film, both at 500°C) than that of microcrystalline, bulk samples ( S/cm at 500°C). The activation energy for the conduction is found to be 0.83 eV for the bulk material, while...

  3. Pulsed Laser Deposition of Cr2-x Fe x TeO 6 Thin Film

    Science.gov (United States)

    Wang, Junlei; Belashchenko, Kirill D.; Dowben, Peter A.; Binek, Christian

    2011-03-01

    Promising spintronic concepts such as Cr 2 O3 based voltage-controlled exchange bias system employ electric controlled boundary magnetization. Symmetry arguments reveal that equilibrium boundary magnetization is a generic property of magnetoelectric antiferromagnets. However, experimental evidence of the boundary magnetization is scarce. Here we explore non-traditional growth of magnetoelectric oxides with tri-rutile structure using pulsed laser deposition (PLD) methodology. We grow and characterize structurally and magnetically various magnetoelectric thin films of the Cr 2-x Fe x Te O6 family starting from x=2 in order to take advantage of the reduced chemical complexity of Fe 2 Te O6 and the beneficial high temperature onset of antiferromagnetic order at 230K in comparison to 90K of Cr 2 Te O6 . Our investigation aims on an experimental test of the predicted generality of the equilibrium boundary magnetization in magnetoelectric antiferromagnets. This project is supported by MRSEC Supplement.

  4. Epitaxial oxide thin films by pulsed laser deposition: Retrospect and prospect

    Indian Academy of Sciences (India)

    M S Hegde

    2001-10-01

    Pulsed laser deposition (PLD) is a unique method to obtain epitaxial multi-component oxide films. Highly stoichiometric, nearly single crystal-like materials in the form of films can be made by PLD. Oxides which are synthesized at high oxygen pressure can be made into films at low oxygen partial pressure. Epitaxial thin films of high c cuprates, metallic, ferroelectric, ferromagnetic, dielectric oxides, super conduc tor-metal-superconductor Josephson junctions and oxide superlattices have been made by PLD. In this article, an overview of preparation, characterization and properties of epitaxial oxide films and their applications are presented. Future prospects of the method for fabricating epitaxial films of transition metal nitrides, chalcogenides, carbides and borides are discussed.

  5. Fabrication of pulsed-laser deposited V-W-Nd mixed-oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Iida, Yusuke; Venkatachalam, S.; Kaneko, Yoshikazu [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511 (Japan); Kanno, Yoshinori [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511 (Japan)], E-mail: kanno@yamanashi.ac.jp

    2007-11-15

    V-W-Nd mixed-oxide films were prepared by pulse-laser deposition (PLD) technique from the targets sintered at different temperatures. X-ray photoelectron spectroscopy (XPS) data indicate that the films fabricated from the targets sintered at low temperature were composed of various mixed valences. Raman spectroscopy shows that V-W-Nd films were composed of the vanadates as NdVO{sub 4}, and the W{sup 6+} doping supplements the formation of vanadate. Atomic force microscopy (AFM) image of the films fabricated from the target sintered at 923 K reveals the average particle size is estimated around 86 nm. The surface morphology of the films roughness shows a dramatic change at 923-943 K.

  6. Fabrication of EuTiO3 Epitaxial Thin Films by Pulsed Laser Deposition

    Science.gov (United States)

    Hatabayashi, Kunitada; Hitosugi, Taro; Hirose, Yasushi; Cheng, Xianqiang; Shimada, Toshihiro; Hasegawa, Tetsuya

    2009-10-01

    We have fabricated high-quality epitaxial EuTiO3(100) films on SrTiO3 substrates by pulsed laser deposition. In situ reflection high-energy electron diffraction (RHEED) monitoring revealed clear intensity oscillation, indicating layer-by-layer growth of EuTiO3. Furthermore, the obtained films had atomically flat surfaces with a step-terrace structure. From magnetization vs temperature measurements, we confirmed that the EuTiO3 films have antiferromagnetic ordering with a Néel temperature of 3.7 K, and that they could be transformed to a ferromagnetic state by applying a magnetic field. We also found that the magnetic properties of the EuTiO3 films are sensitive to cell volume, as predicted by recent first-principles band calculations.

  7. Tight comparison of Mg and Y thin film photocathodes obtained by the pulsed laser deposition technique

    Science.gov (United States)

    Lorusso, A.; Gontad, F.; Solombrino, L.; Chiadroni, E.; Broitman, E.; Perrone, A.

    2016-11-01

    In this work Magnesium (Mg) and Yttrium (Y) thin films have been deposited on Copper (Cu) polycrystalline substrates by the pulsed laser ablation technique for photocathode application. Such metallic materials are studied for their interesting photoemission properties and are proposed as a good alternative to the Cu photocathode, which is generally used in radio-frequency guns. Mg and Y films were uniform with no substantial differences in morphology; a polycrystalline structure was found for both of them. Photoemission measurements of such cathodes based on thin films were performed, revealing a quantum efficiency higher than Cu bulk. Photoemission theory according to the three-step model of Spicer is invoked to explain the superior photoemission performance of Mg with respect to Y.

  8. RAPID COMMUNICATION: ? thin film bilayers grown by pulsed laser ablation deposition

    Science.gov (United States)

    Singh, S. K.; Palmer, S. B.; McK Paul, D.; Lees, M. R.

    1996-09-01

    We have grown superconducting thin films of 0022-3727/29/9/044/img2 (Y-123) on 0022-3727/29/9/044/img3 (PCMO) buffer layers and PCMO overlayers on Y-123 thin films using pulsed laser ablation deposition. For both sets of films below 50 K, the Y-123 layer is superconducting and the zero-field cooled PCMO layer is insulating. The application of a magnetic field of 8 T results in an insulator - metal transition in the PCMO layer. This field-induced conducting state is stable in zero magnetic field at low temperature. The PCMO layer can be returned to an insulating state by annealing above 100 K. This opens the way for the construction of devices incorporating these oxide materials in which the electronic properties of key components such as the substrate or the barrier layer can be switched in a controlled way by the application of a magnetic field.

  9. Crystallization and oxygen loading in pulsed laser deposited YSZ-films

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Benedikt; Liese, Tobias; Hoffmann, Sarah; Krebs, Hans-Ulrich [Institut fuer Materialphysik, University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

    2011-07-01

    Yttria-stabilized zirconium dioxide (YSZ) as an oxygen ion conductor is widely used in technical applications, for example as solid oxide fuel cells. Thus, it is important studying the film stability at higher temperatures. In this contribution, amorphous YSZ films prepared by Pulsed Laser Deposition (PLD) at room temperature and annealed in argon/vacuum or oxygen atmosphere are presented. In a first thermal treatment in high vacuum up to temperatures of 800 C a loss of oxygen and crystallization of the film is achieved. Further heating in oxygen atmosphere leads to a reversible reloading of oxygen in the film. At this, changing the heating time and temperature enables to obtain different levels of oxygen in the samples. The weight change during outgasing and reloading was measured by thermal gravimetric analysis (TGA). The structure of different oxygen states and dynamics of crystallization was characterized by in-situ X-ray diffraction (XRD) and ellipsometry.

  10. Dielectric dilatometry on thin Teflon-PTFE films prepared by pulsed-laser deposition

    Science.gov (United States)

    Schwoediauer, Reinhard; Bauer-Gogonea, Simona; Bauer, Stefan; Heitz, J.; Arenholz, Enno; Baeuerle, Dieter

    1999-12-01

    Polytetrafluoroethylene (Teflon PTFE) films were grown by pulsed-laser deposition (PLD). Films prepared by ablation from press-sintered targets are found to be highly crystalline, with spherulite sizes adjustable over more than one order in magnitude by suitable thermal annealing. As revealed by dielectric dilatometry, PLD-PTFE films show characteristics remarkably similar to those of conventional PTFE, i.e. the same structural first-order phase transitions. Dielectric losses are low and indicate no tendency to film oxidation. PLD-PTFE films additionally show an excellent charge-stability, comparable and even superior to commercially available Teflon-PTFE foils. PLD-PTFE enlarges the family of Teflon materials and may thus become interesting for potential miniaturized electret devices. Furthermore, dielectric dilatometry provides an elegant means for the determination of the coefficient of thermal expansion in thin nonpolar films.

  11. Pulsed laser deposition of high-quality thin films of the insulating ferromagnet EuS

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qi I., E-mail: qiyang@stanford.edu [Department of Physics, Stanford University, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Zhao, Jinfeng; Risbud, Subhash H. [Department of Chemical Engineering and Materials Science, University of California, Davis, California 95616 (United States); Zhang, Li; Dolev, Merav [Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Fried, Alexander D. [Department of Physics, Stanford University, Stanford, California 94305 (United States); Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Marshall, Ann F. [Stanford Nanocharacterization Laboratory, Stanford University, Stanford, California 94305 (United States); Kapitulnik, Aharon [Department of Physics, Stanford University, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States)

    2014-02-24

    High-quality thin films of the ferromagnetic insulator europium(II) sulfide (EuS) were fabricated by pulsed laser deposition on Al{sub 2}O{sub 3} (0001) and Si (100) substrates. A single orientation was obtained with the [100] planes parallel to the substrates, with atomic-scale smoothness indicates a near-ideal surface topography. The films exhibit uniform ferromagnetism below 15.9 K, with a substantial component of the magnetization perpendicular to the plane of the films. Optimization of the growth condition also yielded truly insulating films with immeasurably large resistance. This combination of magnetic and electric properties opens the gate for future devices that require a true ferromagnetic insulator.

  12. Pulsed-laser deposition of nanostructured iron oxide catalysts for efficient water oxidation.

    Science.gov (United States)

    Orlandi, Michele; Caramori, Stefano; Ronconi, Federico; Bignozzi, Carlo A; El Koura, Zakaria; Bazzanella, Nicola; Meda, Laura; Miotello, Antonio

    2014-05-14

    Amorphous iron oxide nanoparticles were synthesized by pulsed-laser deposition (PLD) for functionalization of indium-tin oxide surfaces, resulting in electrodes capable of efficient catalysis in water oxidation. These electrodes, based on earth-abundant and nonhazardous iron metal, are able to sustain high current densities (up to 20 mA/cm2) at reasonably low applied potential (1.64 V at pH 11.8 vs reversible hydrogen electrode) for more than 1 h when employed as anodes for electrochemical water oxidation. The good catalytic performance proves the validity of PLD as a method to prepare nanostructured solid-state materials for catalysis, enabling control over critical properties such as surface coverage and morphology.

  13. Laser-induced fluorescence analysis of plasmas for epitaxial growth of YBiO3 films with pulsed laser deposition

    Science.gov (United States)

    Orsel, Kasper; Groenen, Rik; Bastiaens, Bert; Koster, Gertjan; Rijnders, Guus; Boller, Klaus-J.

    2016-12-01

    We record the two-dimensional laser-induced fluorescence (LIF) on multiple plasma constituents in a YBiO3 plasma. This allows us to directly link the influence of oxygen present in the background gas during pulsed laser deposition to the oxidation of plasma species as well as the formation of epitaxial YBiO3 films. With spatiotemporal LIF mapping of the plasma species (Y, YO, Bi, and BiO) in different background gas compositions, we find that little direct chemical interaction takes place between the plasma plume constituents and the background gas. However, a strong influence of the background gas composition can be seen on the YBO film growth, as well as a strong correlation between the oxygen fraction in the background gas and the amount of YO in the plasma plume. We assign this correlation to a direct interaction between the background gas and the target in between ablation pulses. In an O2 background, an oxygen-rich surface layer forms in between ablation pulses, which provides additional oxygen for the plasma plume during target ablation. This differs from our previous observations in STO and LAO plasmas, where species oxidation primarily takes place during propagation of the plasma plume towards the substrate.

  14. Laser-induced fluorescence analysis of plasmas for epitaxial growth of YBiO3 films with pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    Kasper Orsel

    2016-12-01

    Full Text Available We record the two-dimensional laser-induced fluorescence (LIF on multiple plasma constituents in a YBiO3 plasma. This allows us to directly link the influence of oxygen present in the background gas during pulsed laser deposition to the oxidation of plasma species as well as the formation of epitaxial YBiO3 films. With spatiotemporal LIF mapping of the plasma species (Y, YO, Bi, and BiO in different background gas compositions, we find that little direct chemical interaction takes place between the plasma plume constituents and the background gas. However, a strong influence of the background gas composition can be seen on the YBO film growth, as well as a strong correlation between the oxygen fraction in the background gas and the amount of YO in the plasma plume. We assign this correlation to a direct interaction between the background gas and the target in between ablation pulses. In an O2 background, an oxygen-rich surface layer forms in between ablation pulses, which provides additional oxygen for the plasma plume during target ablation. This differs from our previous observations in STO and LAO plasmas, where species oxidation primarily takes place during propagation of the plasma plume towards the substrate.

  15. Fabrication of nano-engineered transparent conducting oxides by pulsed laser deposition.

    Science.gov (United States)

    Gondoni, Paolo; Ghidelli, Matteo; Di Fonzo, Fabio; Li Bassi, Andrea; Casari, Carlo S

    2013-02-27

    Nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas allows the deposition of metal oxides with tunable morphology, structure, density and stoichiometry by a proper control of the plasma plume expansion dynamics. Such versatility can be exploited to produce nanostructured films from compact and dense to nanoporous characterized by a hierarchical assembly of nano-sized clusters. In particular we describe the detailed methodology to fabricate two types of Al-doped ZnO (AZO) films as transparent electrodes in photovoltaic devices: 1) at low O₂ pressure, compact films with electrical conductivity and optical transparency close to the state of the art transparent conducting oxides (TCO) can be deposited at room temperature, to be compatible with thermally sensitive materials such as polymers used in organic photovoltaics (OPVs); 2) highly light scattering hierarchical structures resembling a forest of nano-trees are produced at higher pressures. Such structures show high Haze factor (>80%) and may be exploited to enhance the light trapping capability. The method here described for AZO films can be applied to other metal oxides relevant for technological applications such as TiO₂, Al₂O₃, WO₃ and Ag₄O₄.

  16. Interface control by homoepitaxial growth in pulsed laser deposited iron chalcogenide thin films

    Science.gov (United States)

    Molatta, Sebastian; Haindl, Silvia; Trommler, Sascha; Schulze, Michael; Wurmehl, Sabine; Hühne, Ruben

    2015-11-01

    Thin film growth of iron chalcogenides by pulsed laser deposition (PLD) is still a delicate issue in terms of simultaneous control of stoichiometry, texture, substrate/film interface properties, and superconducting properties. The high volatility of the constituents sharply limits optimal deposition temperatures to a narrow window and mainly challenges reproducibility for vacuum based methods. In this work we demonstrate the beneficial introduction of a semiconducting FeSe1-xTex seed layer for subsequent homoepitaxial growth of superconducting FeSe1-xTex thin film on MgO substrates. MgO is one of the most favorable substrates used in superconducting thin film applications, but the controlled growth of iron chalcogenide thin films on MgO has not yet been optimized and is the least understood. The large mismatch between the lattice constants of MgO and FeSe1-xTex of about 11% results in thin films with a mixed texture, that prevents further accurate investigations of a correlation between structural and electrical properties of FeSe1-xTex. Here we present an effective way to significantly improve epitaxial growth of superconducting FeSe1-xTex thin films with reproducible high critical temperatures (≥17 K) at reduced deposition temperatures (200 °C-320 °C) on MgO using PLD. This offers a broad scope of various applications.

  17. Nano-cube MgO formed on silicon substrate using pulsed laser deposition.

    Science.gov (United States)

    Kaneko, Satoru; Ito, Takeshi; Akiyama, Kensuke; Yasui, Manabu; Hirabayashi, Yasuo; Soga, Masayasu; Miyake, Yumiko; Yoshimoto, Mamoru

    2012-03-01

    Nano-cube MgO particles were formed on Si substrates by deposition of an MgO target using pulsed laser deposition method. An epitaxial film grows on Si(001) substrate with its contraction of lattice constants. In this study, expecting high quality MgO film, the MgO film prepared in the oxygen pressure ranging from 75-400 mTorr at the high temperature of -750 degrees C. The deposited MgO showed the growth of (001) preferred orientation on the Si(001) substrate. However, X-ray Photoelectron Spectroscopy (XPS) indicated the MgO film did not form a continuous film on the Si surface. Interestingly, the surface morphology observed by an Atomic Force Microscopy (AFM) showed nano-cube MgO particles scattered on the smooth surface of Si substrate. After annealing the nano-cube MgO, the shape of MgO particles were changed from nano-cube to round shaped particles. The AFM image of the surface showed round shaped MgO nanoparticles scattered on rough surface. X-ray Diffraction (XRD) revealed the epitaxial growth of MgO(001) with cubic on cubic arrangement on the Si(001) substrate (MgO[100] parallel to Si[100]).

  18. Vacuum ultraviolet annealing of thin films grown by pulsed laser deposition

    Science.gov (United States)

    Craciun, Valentin; Craciun, Doina; Andreazza, Pascal; Perriere, Jacques; Boyd, Ian W.

    1999-01-01

    The effect of a post-deposition annealing treatment in 1 bar of oxygen at moderate temperatures (excimer lamp upon thin ZrO 2 and hydroxyapatite (HAp) films grown by the pulsed laser deposition (PLD) technique was investigated. The optical and structural properties of the films were improved by this treatment, the lower the deposition temperature and, accordingly, the poorer the initial characteristics, the more significant the improvements. The combination of these two techniques allowed us to obtain at temperatures below 350°C highly textured (020) ZrO 2 films, exhibiting optical absorption coefficients lower than 5×10 2 cm -1 and high refractive index values of around 2.25 in the visible region of the spectrum. The VUV treatment was also beneficial for the partially crystalline HAp layers containing tetracalcium phosphate and calcium oxide phases grown by the PLD technique under a low pressure oxidising atmosphere of only 10 -5 torr without any water vapours. After the VUV-assisted anneal, the crystalline structure and the stoichiometry greatly improved while the percentage of the other crystalline phases initially present was many times reduced.

  19. Structural and Magnetic Properties of Mn doped ZnO Thin Film Deposited by Pulsed Laser Deposition

    KAUST Repository

    Baras, Abdulaziz

    2011-07-01

    Diluted magnetic oxide (DMO) research is a growing field of interdisciplinary study like spintronic devices and medical imaging. A definite agreement among researchers concerning the origin of ferromagnetism in DMO has yet to be reached. This thesis presents a study on the structural and magnetic properties of DMO thin films. It attempts to contribute to the understanding of ferromagnetism (FM) origin in DMO. Pure ZnO and Mn doped ZnO thin films have been deposited by pulsed laser deposition (PLD) using different deposition conditions. This was conducted in order to correlate the change between structural and magnetic properties. Structural properties of the films were characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM). The superconducting quantum interference device (SQUID) was used to investigate the magnetic properties of these films. The structural characterizations showed that the quality of pure ZnO and Mn doped ZnO films increased as oxygen pressure (PO) increased during deposition. All samples were insulators. In Mn doped films, Mn concentration decreased as PO increased. The Mn doped ZnO samples were deposited at 600˚C and oxygen pressure from 50-500mTorr. All Mn doped films displayed room temperature ferromagnetism (RTFM). However, at 5 K a superparamagnetic (SPM) behavior was observed in these samples. This result was accounted for by the supposition that there were secondary phase(s) causing the superparamagnetic behavior. Our findings hope to strengthen existing research on DMO origins and suggest that secondary phases are the core components that suppress the ferromagnetism. Although RTFM and SPM at low temperature has been observed in other systems (e.g., Co doped ZnO), we are the first to report this behavior in Mn doped ZnO. Future research might extend the characterization and exploration of ferromagnetism in this system.

  20. Perpendicularly oriented barium ferrite thin films with low microwave loss, prepared by pulsed laser deposition

    Science.gov (United States)

    Da-Ming, Chen; Yuan-Xun, Li; Li-Kun, Han; Chao, Long; Huai-Wu, Zhang

    2016-06-01

    Barium ferrite (BaM) thin films are deposited on platinum coated silicon wafers by pulsed laser deposition (PLD). The effects of deposition substrate temperature on the microstructure, magnetic and microwave properties of BaM thin films are investigated in detail. It is found that microstructure, magnetic and microwave properties of BaM thin film are very sensitive to deposition substrate temperature, and excellent BaM thin film is obtained when deposition temperature is 910 °C and oxygen pressure is 300 mTorr (1 Torr = 1.3332 × 102 Pa). X-ray diffraction patterns and atomic force microscopy images show that the best thin film has perpendicular orientation and hexagonal morphology, and the crystallographic alignment degree can be calculated to be 0.94. Hysteresis loops reveal that the squareness ratio (M r/M s) is as high as 0.93, the saturated magnetization is 4004 Gs (1 Gs = 104 T), and the anisotropy field is 16.5 kOe (1 Oe = 79.5775 A·m-1). Ferromagnetic resonance measurements reveal that the gyromagnetic ratio is 2.8 GHz/kOe, and the ferromagnetic resonance linewith is 108 Oe at 50 GHz, which means that this thin film has low microwave loss. These properties make the BaM thin films have potential applications in microwave devices. Project supported by the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices (Grant No. KFJJ201506), the Scientific Research Starting Foundation of Hainan University (Grant No. kyqd1539), and the Natural Science Foundation of Hainan Province (Grant No. 20165187).

  1. n-type In2S3 films deposited by pulsed laser deposition: effect of laser power on the properties of the films

    Science.gov (United States)

    Wu, Chunyan; Mao, Dun; Liu, Zhu; Liang, Qi; Chen, Shirong; Yu, Yongqiang; Wang, Li; Luo, Linbao; Xu, Jun

    2015-05-01

    Pulsed laser deposition (PLD) with different levels of laser power was first used to deposit In2S3 films from homemade, high-purity In2S3 targets. This process was followed by post-annealing in an N2 atmosphere to improve the films’ crystallinity and conductivity. The annealed films were verified to be stoichiometric, body-centered, tetragonal In2S3 with the preferred orientation (103). The bandgap of the films decreased from 2.8 to 2.2 eV with an increase in the laser power, which was believed to be the result of the grain growth caused by the higher laser power. The electrical transport property of the bottom-gate field-effect transistor revealed the n-type conduction of the annealed In2S3 films, and the heterojunction p+-Si/annealed In2S3 film showed remarkable photovoltaic behavior upon light illumination, indicating that PLD-deposited In2S3 films may have great potential as a buffer layer in thin-film solar cells. What’s more, doped In2S3 films can be easily realized due to the fairly stoichiometric transfer of the PLD method.

  2. Temperature dependent photoreflectance study of Cu2SnS3 thin films produced by pulsed laser deposition

    DEFF Research Database (Denmark)

    Raadik, T.; Grossberg, M.; Krustok, J.

    2017-01-01

    The energy band structure of Cu2SnS3 (CTS) thin films fabricated by pulsed laser deposition was studied by photoreflectance spectroscopy (PR). The temperature-dependent PR spectra were measured in the range of T = 10–150 K. According to the Raman scattering analysis, the monoclinic crystal...

  3. Broadband single-transverse-mode fluorescence sources based on ribs fabricated in pulsed laser deposited Ti: sapphire waveguides

    NARCIS (Netherlands)

    Grivas, C.; May-Smith, T.C.; Shepherd, D.P.; Eason, R.W.; Pollnau, M.; Jelinek, M.

    2004-01-01

    Active rib waveguides with depths and widths varying from 3 to 5 μm and from 9 to 24 μm, respectively, have been structured by $Ar^{+}$-beam etching in pulsed laser deposited Ti:sapphire layers. Losses in the channel structures were essentially at the same levels as the unstructured planar waveguide

  4. Thickness determination of large-area films of yttria-stabilized zirconia produced by pulsed laser deposition

    DEFF Research Database (Denmark)

    Pryds, N.; Christensen, Bo Toftmann; Bilde-Sørensen, Jørgen;

    2006-01-01

    Films of yuria-stabilized zirconia (YSZ) on a polished silicon substrate of diameter up to 125 mm have been produced in a large-area pulsed laser deposition (PLD) setup under typical PLD conditions. The film thickness over the full film area has been determined by energy-dispersive Xray spectrome...

  5. Annealing Effect of Pulsed Laser Deposited Transparent Conductive Ta-Doped Titanium Oxide Films

    Institute of Scientific and Technical Information of China (English)

    WU Bin-Bin; PAN Feng-Ming; YANG Yu-E

    2011-01-01

    Tantalum-doped TiO2 Rilms were deposited on glass at 300℃PG by pulsed laser deposition (PLD). After post-annealing in vacuum (~10-4 Pa) at temperatures ranging from 450℃ to 650℃, these films were crystallized into an anatase TiO2 structure and presented good conductive features. With increasing annealing temperature up to 550℃, the resistivity of the films was measured to be around 8.7 x 10-4 Ω·cm. Such films exhibit high transparency of over 80% in the visible light region. These results indicate that tantalum-doped anatase TiO2 films have a great potential as transparent conducting oxides.%Tantalum-doped TiO2 films were deposited on glass at 300℃ by pulsed laser deposition (PLD).After postannealing in vacuum (~10-4 Pa) at temperatures ranging from 450℃ to 650℃,these films were crystallized into an anatase TiO2 structure and presented good conductive features.With increasing annealing temperature up to 550℃,the resistivity of the films was measured to be around 8.7 × 10-4 Ω·cm.Such films exhibit high transparency of over 80% in the visible light region.These results indicate that tantalum-doped anatase TiO2 films have a great potential as transparent conducting oxides.Transparent conducting oxides (TCOs) have received much attention both in fundamental research and device applications due to their good combination of high electrical conductivity and excellent optical transparency.[1] Among various TCOs,indium tin oxide (ITO) is considered as the most beneficial TCO due to its excellent properties:low resistivity (~10-4 Ω·cm),high optical transmittance (80-90%)and simple preparation process.[2] However,due to the scarcity and high cost of indium,ITO may not be able to satisfy the demands in the future.Hence,it is necessary to explore new candidates of TCOs for expanding application usage.

  6. Growth of doped silicon nanowires by pulsed laser deposition and their analysis by electron beam induced current imaging

    Energy Technology Data Exchange (ETDEWEB)

    Eisenhawer, B; Berger, A; Christiansen, S [Institute of Photonic Technology, Albert-Einstein-Strasse 9, 07745 Jena (Germany); Zhang, D; Clavel, R [Laboratory of Robotic Systems, Ecole Polytechnique Federale de Lausanne (EPFL), Station 9, CH-1015 Lausanne (Switzerland); Michler, J, E-mail: bjoern.eisenhawer@ipht-jena.de [Mechanics of Materials and Nanostructures Laboratory, EMPA-Materials Science and Technology, Feuerwerkstrasse 39, CH-3602 Thun (Switzerland)

    2011-02-18

    Doped silicon nanowires (NWs) were epitaxially grown on silicon substrates by pulsed laser deposition following a vapour-liquid-solid process, in which dopants together with silicon atoms were introduced into the gas phase by laser ablation of lightly and highly doped silicon target material. p-n or p{sup ++}-p junctions located at the NW-silicon substrate interfaces were thus realized. To detect these junctions and visualize them the electron beam induced current technique and two-point probe current-voltage measurements were used, based on nanoprobing individual silicon NWs in a scanning electron microscope. Successful silicon NW doping by pulsed laser deposition of doped target material could experimentally be demonstrated. This doping strategy compared to the commonly used doping from the gas phase during chemical vapour deposition is evaluated essentially with a view to potentially overcoming the limitations of chemical vapour deposition doping, which shows doping inhomogeneities between the top and bottom of the NW as well as between the core and shell of NWs and structural lattice defects, especially when high doping levels are envisaged. The pulsed laser deposition doping technique yields homogeneously doped NWs and the doping level can be controlled by the choice of the target material. As a further benefit, this doping procedure does not require the use of poisonous gases and may be applied to grow not only silicon NWs but also other kinds of doped semiconductor NWs, e.g. group III nitrides or arsenides.

  7. Pulsed Laser Deposition ZnS Buffer Layers for CIGS Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Pai-feng Luo; Guo-shun Jiang; Chang-fei Zhu

    2009-01-01

    Polycrystalline ZnS films were prepared by pulsed laser deposition (PLD) on quartz glass substrates under different growth conditions at different substrate temperatures of 20, 200, 400, and 600 ℃, which is a suitable alternative to chemical bath deposited (CBD) CdS as a buffer layer in Cu(In,Ga)Se2 (CIGS) solar cells. X-ray diffraction studies indicate the films are polycrystalline with zinc-blends structure and they exhibit preferential orientation along the cubic phase β-ZnS (111) direction, which conflicts with the conclusion of wurtzite struc-ture by Murali that the ZnS films deposited by pulse plating technique was polycrystalline with wurtzite structure. The Raman spectra of grown films show A1 mode at approxi-mately 350 cm-1, generally observed in the cubic phase β-ZnS compounds. The planar and the cross-sectional morphology were observed by scanning electron microscopic. The dense, smooth, uniform grains are formed on the quartz glass substrates through PLD technique. The grain size of ZnS deposited by PLD is much smaller than that of CdS by conventional CBD method, which is analyzed as the main reason of detrimental cell performance. The composition of the ZnS films was also measured by X-ray fluorescence. The typical ZnS films obtained in this work are near stoichiometric and only a small amount of S-rich. The energy band gaps at different temperatures were obtained by absorption spectroscopy measurement, which increases from 3.2 eV to 3.7 eV with the increasing of the deposition temperature. ZnS has a wider energy band gap than CdS (2.4 eV), which can enhance the blue response of the photovoltaic cells. These results show the high-quality of these substitute buffer layer materials are prepared through an all-dry technology, which can be used in the manufacture of CIGS thin film solar cells.

  8. Growth of γ-alumina thin films by pulsed laser deposition and plasma diagnostic

    Science.gov (United States)

    Yahiaoui, K.; Abdelli-Messaci, S.; Messaoud Aberkane, S.; Siad, M.; Kellou, A.

    2017-07-01

    The present work discusses about the synthesis of alumina thin films, which have applications in current and next-generation solid-state electronic devices due to their attractive properties. Alumina thin films were synthesized by pulsed laser deposition at different oxygen pressures and substrate temperatures. The dependence of substrate temperature, oxygen pressure, and the deposition time on the properties of the films has been observed by growing three series of alumina thin films on Si (100). The first films are synthesized using substrate temperatures ranging from room temperature to 780 °C at 0.01 mbar of O2. The second series was realized at a fixed substrate temperature of 760 °C and varied oxygen pressure (from 0.005 to 0.05 mbar). The third set of series was elaborated at different deposition times (from 15 to 60 min) while the oxygen pressure and the substrate temperature were fixed at 0.01 mbar and 760 °C, respectively. The films were characterized using X-ray diffractometer (XRD) for structural analysis, a scanning electron microscope for morphological analysis, a nano-indenter for mechanical analysis (hardness and Young's modulus), and Rutherford backscattering spectroscopy for thickness and stoichiometry measurements. Using optical emission spectroscopy, plasma diagnostic was carried out both in the vacuum and in the presence of oxygen with a pressure ranging from 0.01 to 0.05 mbar. Several neutral, ionic, and molecular species were identified such as Al, Al+, and Al++ in vacuum and in oxygen ambiance, O and AlO molecular bands in oxygen-ambient atmosphere. The spatiotemporal evolution of the most relevant species was achieved and their velocities were estimated. The highest amount of crystallized alumina in γ-phase was found in the films elaborated under 0.01 mbar of O2, at a substrate temperature of 780 °C, and a deposition time of 60 min.

  9. Development of long Y-123 coated conductors by ion-beam-assisted-deposition and the pulsed-laser-deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Iijima, Yasuhiro; Kakimoto, Kazuomi; Sutoh, Yasunori; Ajimura, Shoji; Saitoh, Takashi [Material Technology Laboratory, Fujikura Ltd, 1-5-1, Kiba, Koto-ku, Tokyo 135-8512 (Japan)

    2004-05-01

    100 m class Y-123 coated conductors were produced by using reel-to-reel vacuum ion-beam-assisted-deposition (IBAD) and pulsed-laser-deposition (PLD) apparatuses. 100 m long IBAD-Gd{sub 2}Zr{sub 2}O{sub 7} template films were uniformly and routinely obtained on non-textured Ni-alloy tapes, with FWHM of {delta}{phi} below 10 deg. Y-123 films with FWHM of {delta}{phi} below 7 deg. were formed on them by PLD. End-to-end I{sub c} of 38 A and J{sub c} of 0.76 MA cm{sup -2} (77 K, self-field) were obtained in a 100 m long sample. For further texture improvement, secondary buffer layers of CeO{sub 2} and Gd{sub 2}Zr{sub 2}O{sub 7} grown by PLD on IBAD-Gd{sub 2}Zr{sub 2}O{sub 7} template films were studied. {delta}{phi} of 3 deg. and J{sub c} of 2.9 MA cm{sup -2} were obtained in a 0.1 m long Y-123 film and J{sub c} improved to 1.6 MA cm{sup -2} for an 80 m long Y-123 tape by using the CeO{sub 2} buffer layers.

  10. Quantitative analysis of amorphous indium zinc oxide thin films synthesized by Combinatorial Pulsed Laser Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Axente, E.; Socol, G.; Luculescu, C.R.; Craciun, V. [National Institute for Lasers, Plasma and Radiation Physics, Laser-Surface-Plasma Interactions Laboratory, Lasers Department, Magurele-Bucharest (Romania); Beldjilali, S.A. [LP3, CNRS-Aix-Marseille University, Marseille (France); LPPMCA, USTOMB-Universite des Sciences et de la Technologie d' Oran, BP 1505, Oran (Algeria); Mercadier, L.; Hermann, J. [LP3, CNRS-Aix-Marseille University, Marseille (France); Trinca, L.M.; Galca, A.C. [National Institute of Materials Physics, Laboratory of Multifunctional Materials and Structures, Magurele-Bucharest (Romania); Pantelica, D.; Ionescu, P. [National Institute of Physics and Nuclear Engineering Horia Hulubei, Magurele-Bucharest (Romania); Becherescu, N. [Apel Laser, Bucharest (Romania)

    2014-10-15

    The use of amorphous and transparent oxides is a key for the development of new thin film transistors and displays. Recently, indium zinc oxide (IZO) was shown to exhibit high transparency in the visible range, low resistivity, and high mobility. Since the properties and the cost of these films depend on the In/(In + Zn) values, the measurement of this ratio is paramount for future developments and applications. We report on accurate analysis of the elemental composition of IZO thin films synthesized using a Combinatorial Pulsed Laser Deposition technique. The monitoring of the thin films elemental composition by Laser-Induced Breakdown Spectroscopy was chosen in view of further in situ and real-time technological developments and process control during IZO fabrication. Our analytical approach is based on plasma modeling, the recorded spectra being then compared to the spectral radiance computed for plasmas in local thermal equilibrium. The cation fractions measured were compared to values obtained by complementary measurements using energy dispersive X-ray spectroscopy and Rutherford backscattering spectrometry. Spectroscopic ellipsometry assisted the scientific discussion. A good agreement between methods was found, independently of the relative fraction of indium and zinc that varied from about 65 to 90 and 35 to 10 at%, respectively, and the measurement uncertainties associated to each analytical method. (orig.)

  11. Transmission of reactive pulsed laser deposited VO2 films in the THz domain

    Science.gov (United States)

    Émond, Nicolas; Hendaoui, Ali; Ibrahim, Akram; Al-Naib, Ibraheem; Ozaki, Tsuneyuki; Chaker, Mohamed

    2016-08-01

    This work reports on the characteristics of the insulator-to-metal transition (IMT) of reactive pulsed laser deposited vanadium dioxide (VO2) films in the terahertz (THz) frequency range, namely the transition temperature TIMT, the amplitude contrast of the THz transmission over the IMT ΔA, the transition sharpness ΔT and the hysteresis width ΔH. XRD analysis shows the sole formation of VO2 monoclinic structure with an enhancement of (011) preferential orientation when varying the O2 pressure (PO2) during the deposition process from 2 to 25 mTorr. THz transmission measurements as a function of temperature reveal that VO2 films obtained at low PO2 exhibit low TIMT, large ΔA, and narrow ΔH. Increasing PO2 results in VO2 films with higher TIMT, smaller ΔA, broader ΔH and asymmetric hysteresis loop. The good control of the VO2 IMT features in the THz domain could be further exploited for the development of advanced smart devices, such as ultrafast switches, modulators, memories and sensors.

  12. Nucleation mechanism and microstructural assessment of SnO2 nanowires prepared by pulsed laser deposition

    Science.gov (United States)

    Chen, Z. W.; Lai, J. K. L.; Shek, C. H.

    2005-10-01

    Tin dioxide, SnO2, nanowires have been successfully synthesized by a pulsed laser deposition process based on a sintered cassiterite SnO2 target, being deposited on Si (100) substrates at room temperature. Transmission electron microscopy shows that nanowires are structurally perfect and uniform, and diameters range from 10 nm to 30 nm, and lengths of several hundreds nanometers to a few micrometers. X-ray diffraction and energy dispersive X-ray spectroscopy analysis indicate that the nanowires have the same crystal structure and chemical composition found in the tetragonal rutile form of SnO2. Selected area electron diffraction and high-resolution transmission electron microscopy reveal that the nanowires grow along the [110] growth direction. In addition to the fundamental Raman scattering peaks, the other two Raman scattering peaks are also observed. We discussed the possible reasons for the appearance of Raman scattering peaks at 518.7 and 701.8 cm-1. The growth process of the SnO2 nanowires is suggested to follow a vapor solid mechanism.

  13. Synthesis and characterization of PLZT thin films obtained by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Verardi, P.; Craciun, F. [CNR Istituto di Acustica, Via del Fosso del Cavaliere 100, 00133, Rome (Italy); Scarisoreanu, N.; Epurescu, G.; Dinescu, M.; Vrejoiu, I. [National Institute for Lasers, Plasma and Radiation Physics (NILPRP), P.O. Box MG-16, 76900, Bucharest (Romania); Dauscher, A. [Laboratoire de Physique des Materiaux (LPM) - UMR CNRS-UHP-INPL 7556, Ecole des Mines, Parc de Saurupt, 54042, Nancy Cedex (France)

    2004-09-01

    Thin films of Pb{sub 1-x}La{sub x}(Zr{sub 0.65}Ti{sub 0.35}){sub 1-x/4}O{sub 3} with x=0.09 (PLZT 9/65/35) have been grown by pulsed laser deposition (PLD) and by PLD assisted by radio frequency (RF) discharge in oxygen which increases the plasma reactivity and reduces the oxygen vacancies in films and at the film-bottom electrode interface. Significant compositional, structural and dielectric differences have been found among samples grown in the same deposition conditions excepting for RF power. Films grown by RF-assisted PLD have less pyrochlore and are more oriented. For these films dielectric permittivity vs. temperature variation was typical of relaxor ferroelectrics and the temperature of the dielectric maximum was close to that obtained in bulk, but the permittivity value was much lower. This was attributed mainly to the influence of a low permittivity interface layer and to the detrimental effect of pyrochlore phase, still present in small quantities even in the films obtained by RF-PLD. The dielectric behavior of films grown without RF discharge was very different: no dielectric anomaly was observed, only a step increase above 180 C. Moreover much higher dielectric loss was measured for these films. (orig.)

  14. Raman spectroscopy of organic dyes adsorbed on pulsed laser deposited silver thin films

    Energy Technology Data Exchange (ETDEWEB)

    Fazio, E.; Neri, F. [Dipartimento di Fisica della Materia e Ingegneria Elettronica, Universitá di Messina, V.le F. Stagno d’Alcontres 31, I-98166, Messina, Italy. (Italy); Valenti, A. [Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Universitá di Messina, V.le F. Stagno d’Alcontres 31, I-98166, Messina, Italy. (Italy); Ossi, P.M., E-mail: paolo.ossi@polimi.it [Dipartimento di Energia, Politecnico di Milano, via Ponzio 34-3, 20133 Milano, Italy. (Italy); Trusso, S.; Ponterio, R.C. [CNR-Istituto per i Processi Chimico-Fisici Sede di Messina, V.le F. Stagno d’Alcontres 37, I-98158 Messina, Italy. (Italy)

    2013-08-01

    The results of a surface-enhanced Raman scattering (SERS) study performed on representative organic and inorganic dyes adsorbed on silver nanostructured thin films are presented and discussed. Silver thin films were deposited on glass slides by focusing the beam from a KrF excimer laser (wavelength 248 nm, pulse duration 25 ns) on a silver target and performing the deposition in a controlled Ar atmosphere. Clear Raman spectra were acquired for dyes such as carmine lake, garanza lake and brazilwood overcoming their fluorescence and weak Raman scattering drawbacks. UV–visible absorption spectroscopy measurements were not able to discriminate among the different chromophores usually referred as carmine lake (carminic, kermesic and laccaic acid), as brazilwood (brazilin and brazilein) and as garanza lake (alizarin and purpurin). SERS measurements showed that the analyzed samples are composed of a mixture of different chromophores: brazilin and brazilein in brazilwood, kermesic and carminic acid in carmine lake, alizarin and purpurin in garanza lake. Detection at concentration level as low as 10{sup −7} M in aqueous solutions was achieved. Higher Raman intensities were observed using the excitation line of 632.8 nm wavelength with respect to the 785 nm, probably due to a pre-resonant effect with the molecular electronic transitions of the dyes.

  15. Enhanced Photocatalytic Performance Depending on Morphology of Bismuth Vanadate Thin Film Synthesized by Pulsed Laser Deposition.

    Science.gov (United States)

    Jeong, Sang Yun; Choi, Kyoung Soon; Shin, Hye-Min; Kim, Taemin Ludvic; Song, Jaesun; Yoon, Sejun; Jang, Ho Won; Yoon, Myung-Han; Jeon, Cheolho; Lee, Jouhahn; Lee, Sanghan

    2017-01-11

    We have fabricated high quality bismuth vanadate (BiVO4) polycrystalline thin films as photoanodes by pulsed laser deposition (PLD) without a postannealing process. The structure of the grown films is the photocatalytically active phase of scheelite-monoclinic BiVO4 which was obtained by X-ray diffraction (XRD) analysis. The change of surface morphology for the BIVO4 thin films depending on growth temperature during synthesis has been observed by scanning electron microscopy (SEM), and its influence on water splitting performance was investigated. The current density of the BiVO4 film grown on a glass substrate covered with fluorine-doped tin oxide (FTO) at 230 °C was as high as 3.0 mA/cm(2) at 1.23 V versus the potential of the reversible hydrogen electrode (VRHE) under AM 1.5G illumination, which is the highest value so far in previously reported BiVO4 films grown by physical vapor deposition (PVD) methods. We expect that doping of transition metal or decoration of oxygen evolution catalyst (OEC) in our BiVO4 film might further enhance the performance.

  16. Pulsed laser deposition of metallic films on the surface of diamond particles for diamond saw blades

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Chao [State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, WuHan, Hubei 430074 (China); Luo Fei [State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, WuHan, HuBei 430074 (China); Long Hua [State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Hu Shaoliu [State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Li Bo [State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Wang Youqing [State Key Laboratory of Laser Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)]. E-mail: lchwan@hust.edu.cn

    2005-06-15

    Ti or Ni films have been deposited on the diamond particle surfaces by pulsed laser deposition. Compressive resistance of the uncoated and coated diamond particles was measured, respectively, in the experiments. The compressive resistance of the Ti-coated diamonds particles was found much higher than that of the uncoated ones. It increased by 39%. The surface morphology is observed by the metallography microscope. The surface of the uncoated diamonds particles had many hollows and flaws, while the surface of Ni-coated diamond particles was flat and smooth, and the surface of Ti-coated diamond particles had some metal masses that stood out of the surface of the Ti-coated film. The components of the metallic films of diamond particles were examined by X-ray diffractometry (XRD). TiC was found formed on the Ti-coated diamond surface, which resulted in increased surface bonding strength between the diamond particles and the Ti films. Meanwhile, TiC also favored improving the bonding strength between the coated diamond particles and the binding materials. Moreover, the bending resistance of the diamond saw blade made of Ti-coated diamond was drastically higher than that of other diamond saw blades, which also played an important role in improving the blade's cutting ability and lifetime. Therefore, it was most appropriate that the diamond saw blade was made of Ti-coated diamond particles rather than other materials.

  17. Facile Synthesis of Porous-Structured Nickel Oxide Thin Film by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Siamak Pilban Jahromi

    2012-01-01

    Full Text Available Porous-structured nickel oxide (PsNiO was obtained through the oxidization of a nickel thin film. The nickel thin film was deposited using the pulsed laser deposition (PLD method on a nickel foil as a substrate. The results show uniform PsNiO after the oxidization of the nickel thin film at 750∘C for 1 h. X-ray diffraction (XRD indicates formation of the NiO crystalline structure. Field emission scanning electron microscopy (FESEM reveals different morphology on the surface of the nickel foil (sample A and on the nickel thin film (sample B. Comparison of the FESEM results after oxidization shows that the PsNiO on the nickel thin film was more regular and controllable than the NiO layer on the nickel foil. The FESEM images also show that the thickness of the nickel thin film affected the PsNiO size obtained after oxidization. This resulted from the growth of the porous structure at grain boundaries and from the grain sizes. The electrochemical properties of the PsNiO as an electrode are investigated by cyclic voltammetry (CV. These results show the effect of PsNiO size on the current of anodic peak.

  18. Pulsed laser deposited FeOF as negative electrodes for rechargeable Li batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yu Le; Wang Haoxuan; Liu Zhiyan [Shanghai Key laboratory of Molecular Catalysts and Innovative Materials, Department of Chemistry and Laser Chemistry Institute, Fudan University, Shanghai, 200433 (China); Fu Zhengwen, E-mail: zwfu@fudan.edu.c [Shanghai Key laboratory of Molecular Catalysts and Innovative Materials, Department of Chemistry and Laser Chemistry Institute, Fudan University, Shanghai, 200433 (China)

    2010-12-30

    FeOF thin film has been successfully fabricated by reactive pulsed laser deposition for the first time, and its electrochemical behavior was examined as a negative electrode active material in lithium-ion batteries. The electrochemical properties of the as-deposited FeOF thin film during the first charging and discharging have been investigated by the galvanostatic cycling and cyclic voltammetry measurements. By using ex situ X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected-area electron diffraction measurements (SAED), it can be found that FeOF was initially decomposed into Fe{sup 0}, LiF, and Fe{sub 2}O{sub 3} after discharging to 1.0 V. The newly formed Fe{sub 2}O{sub 3} is then subsequently reduced into Li{sub 2}O and Fe{sup 0} after further discharging to 0.01 V. In the subsequent cycle, the reduction peaks at 0.76 V and the oxidation-reduction peaks at 1.6 and 1.9 V could be attributed to the reversible decomposition and formation of Li{sub 2}O with the conversion reaction of Fe{sub 2}O{sub 3} into Fe.

  19. Stoichiometry control of complex oxides by sequential pulsed-laser deposition from binary-oxide targets

    Energy Technology Data Exchange (ETDEWEB)

    Herklotz, A. [ORNL, Materials Science and Technology Division, Bethel Valley Road, Oak Ridge, Tennessee 37831-6056 (United States); Martin Luther University Halle-Wittenberg, Institute for Physics, Von-Danckelmann-Platz 3, 06120 Halle (Germany); Dörr, K. [Martin Luther University Halle-Wittenberg, Institute for Physics, Von-Danckelmann-Platz 3, 06120 Halle (Germany); Ward, T. Z.; Eres, G. [ORNL, Materials Science and Technology Division, Bethel Valley Road, Oak Ridge, Tennessee 37831-6056 (United States); Christen, H. M.; Biegalski, M. D. [ORNL, Center for Nanophase Materials Sciences, Bethel Valley Road, Oak Ridge, Tennessee 37831-6496 (United States)

    2015-03-30

    To have precise atomic layer control over interfaces, we examine the growth of complex oxides through the sequential deposition from binary targets by pulsed laser deposition. In situ reflection high-energy electron diffraction (RHEED) is used to control the growth and achieve films with excellent structural quality. The growth from binary oxide targets is fundamentally different from single target growth modes and shows more similarities to shuttered growth by molecular beam epitaxy. The RHEED intensity oscillations of non-stoichiometric growth are consistent with a model of island growth and accumulation of excess material on the surface that can be utilized to determine the correct stoichiometry for growth. Correct monolayer doses can be determined through an envelope frequency in the RHEED intensity oscillations. In order to demonstrate the ability of this growth technique to create complex heterostructures, the artificial n = 2 and 3 Sr{sub n+1}Ti{sub n}O{sub 3n+1} Ruddlesden-Popper phases are grown with good long-range order. This method enables the precise unit-cell level control over the structure of perovskite-type oxides, and thus the growth of complex materials with improved structural quality and electronic functionality.

  20. High performance diamond-like carbon layers obtained by pulsed laser deposition for conductive electrode applications

    Science.gov (United States)

    Stock, F.; Antoni, F.; Le Normand, F.; Muller, D.; Abdesselam, M.; Boubiche, N.; Komissarov, I.

    2017-09-01

    For the future, one of the biggest challenge faced to the technologies of flat panel display and various optoelectronic and photovoltaic devices is to find an alternative to the use of transparent conducting oxides like ITO. In this new approach, the objective is to grow high conductive thin-layer graphene (TLG) on the top of diamond-like carbon (DLC) layers presenting high performance. DLC prepared by pulsed laser deposition (PLD) have attracted special interest due to a unique combination of their properties, close to those of monocrystalline diamond, like its transparency, hardness and chemical inertia, very low roughness, hydrogen-free and thus high thermal stability up to 1000 K. In our future work, we plane to explore the synthesis of conductive TLG on top of insulating DLC thin films. The feasibility and obtained performances of the multi-layered structure will be explored in great details in the short future to develop an alternative to ITO with comparable performance (conductivity of transparency). To select the best DLC candidate for this purpose, we focus this work on the physicochemical properties of the DLC thin films deposited by PLD from a pure graphite target at two wavelengths (193 and 248 nm) at various laser fluences. A surface graphenization process, as well as the required efficiency of the complete structure (TLG/DLC) will clearly be related to the DLC properties, especially to the initial sp3/sp2 hybridization ratio. Thus, an exhaustive description of the physicochemical properties of the DLC layers is a fundamental step in the research of comparable performance to ITO.

  1. Influences of pulse laser parameters on properties of AISI316L stainless steel thin-walled part by laser material deposition

    Science.gov (United States)

    Wang, Xinlin; Deng, Dewei; Yi, Hongli; Xu, Haiyan; Yang, Shuhua; Zhang, Hongchao

    2017-07-01

    Laser material deposition (LMD) which combines laser cladding and rapid prototyping technique has been widely used to build full density metal parts directly without using modules or tools. There are many parameters affecting the quality and properties of the LMD parts through changing the energy distribution. Pulse laser provides the user an added degree of controlling over the energy distribution which seriously affects the solidification of molten pool and eventual part formation. In the present study, a series of AISI316L stainless steel thin-walled parts are successfully produced by LMD with different pulse laser parameters to investigate the effects of energy distribution on characteristics (microstructure, hardness, residual stress and tensile properties). The results show that the characteristics of LMD parts are obviously influenced by laser mode (pulse or continuous wave laser) and pulse laser parameters (T_pulse and T_pause). The microstructure of parts presents various grain sizes with the different pulse laser parameters. The different value (D-value) between the hardness of edge and central region varies considerably with the pulse laser parameters. The maximum D-value of hardness is presented in the part deposited by continuous wave laser. The maximum hardness is presented in item 4 (T_pulse=10 ms, T_pause=10 ms) and the minimum hardness is presented in part fabricated by continuous wave laser where the residual stress on Z-component presents tensile stress at the edge region and compress stress at the central region but opposite trend happens to the residual stress on Y-component. Tensile stress on Z-component at the edge region increases even presents compress tensile with the decrease of T_pulse. The stress on Y-component presents a periodic variation between tensile stress and compress stress in the Y-direction of the part fabricated by pulse laser. The ultimate tensile strength (UTS) of the part fabricated using pulse laser is higher than the

  2. Cr13Ni5Si2-Based Composite Coating on Copper Deposited Using Pulse Laser Induction Cladding.

    Science.gov (United States)

    Wang, Ke; Wang, Hailin; Zhu, Guangzhi; Zhu, Xiao

    2017-02-10

    A Cr13Ni5Si2-based composite coating was successfully deposited on copper by pulse laser induction hybrid cladding (PLIC), and its high-temperature wear behavior was investigated. Temperature evolutions associated with crack behaviors in PLIC were analyzed and compared with pulse laser cladding (PLC) using the finite element method. The microstructure and present phases were analyzed using scanning electron microscopy and X-ray diffraction. Compared with continuous laser induction cladding, the higher peak power offered by PLIC ensures metallurgical bonding between highly reflective copper substrate and coating. Compared with a wear test at room temperature, at 500 °C the wear volume of the Cr13Ni5Si2-based composite coating increased by 21%, and increased by 225% for a NiCr/Cr3C2 coating deposited by plasma spray. This novel technology has good prospects for application with respect to the extended service life of copper mold plates for slab continuous casting.

  3. Negative permittivity of ZnO thin films prepared from aluminum and gallium doped ceramics via pulsed-laser deposition

    OpenAIRE

    M.A. Bodea; Sbarcea, G.; Naik, Gururaj V.; Boltasseva, Alexandra; Klar, T. A.; Pedarnig, J. D.

    2013-01-01

    Aluminum and gallium doped zinc oxide thin films with negative dielectric permittivity in the near infrared spectral range are grown by pulsed laser deposition. Composite ceramics comprising ZnO and secondary phase Al2O3 or Ga2O3 are employed as targets for laser ablation. Films deposited on glass from dense and small-grained ceramic targets show optical transmission larger than 70 % in the visible and reveal an onset of metallic reflectivity in the near infrared at 1100 nm and a crossover to...

  4. Negative permittivity of ZnO thin films prepared from aluminum and gallium doped ceramics via pulsed-laser deposition

    DEFF Research Database (Denmark)

    Bodea, M. A.; Sbarcea, G.; Naik, G. V.

    2013-01-01

    Aluminum and gallium doped zinc oxide thin films with negative dielectric permittivity in the near infrared spectral range are grown by pulsed laser deposition. Composite ceramics comprising ZnO and secondary phase Al2O3 or Ga2O3 are employed as targets for laser ablation. Films deposited on glass...... from dense and small-grained ceramic targets show optical transmission larger than 70 % in the visible and reveal an onset of metallic reflectivity in the near infrared at 1100 nm and a crossover to a negative real part of the permittivity at approximately 1500 nm. In comparison to noble metals, doped...

  5. Pulsed laser deposition of lysozyme: the dependence on shot numbers and the angular distribution

    DEFF Research Database (Denmark)

    Constantinescu, C.; Matei, A.; Schou, Jørgen

    2013-01-01

    . This was verified by matrix-assisted laser desorption ionization (MALDI) spectrometry of thin films deposited on silicon substrates. The deposition rate of lysozyme was found to decrease with the number of shots and was correlated with increasing thermal damage of the lysozyme. This was monitored by measurements...... of the optical reflectivity of dry lysozyme. The angular distribution of the mass deposition can be fitted well by Anisimov’s hydrodynamic model. The total deposited yield over the entire hemisphere from direct laser ablation of lysozyme was estimated from this model and found to be three orders of magnitude...

  6. The importance of the energetic species in pulsed laser deposition for nanostructuring.

    Science.gov (United States)

    Castelo, A; Afonso, C N; Pesce, E; Piscopiello, E

    2012-03-16

    This work reports on the optical and structural properties of nanostructured films formed by Ag nano-objects embedded in amorphous aluminium oxide (a-Al(2)O(3)) prepared by alternate pulsed laser deposition (PLD). The aim is to understand the importance of the energetic species involved in the PLD process for nanostructuring, i.e. for organizing nanoparticles (NPs) in layers or for self-assembling them into nanocolumns (NCls), all oriented perpendicular to the substrate. In order to change the kinetic energy of the species arriving at the substrate, we use a background gas during the deposition of the embedding a-Al(2)O(3) host. It was produced either in vacuum or in a gas pressure (helium and argon) while the metal NPs were always produced in vacuum. The formation of NPs or NCls is easily identified through the features of the surface plasmon resonances (SPR) in the extinction spectra and confirmed by electron microscopy. The results show that both the layer organization and self-assembling of the metal are prevented when the host is produced in a gas pressure. This result is discussed in terms of the deceleration of species arriving at the substrate in gas that reduces the metal sputtering by host species (by ≈58%) as well as the density of the host material (by ≥19%). These reductions promote the formation of large voids along which the metal easily diffuses, thus preventing organization and self-organisation, as well as an enhancement of the amount of metal that is deposited.

  7. Properties of multilayer gallium and aluminum doped ZnO(GZO/AZO)transparent thin films deposited by pulsed laser deposition process

    Institute of Scientific and Technical Information of China (English)

    Jin-Hyum SHIN; Dong-Kyun SHIN; Hee-Young LEE; Jai-Yeoul LEE

    2011-01-01

    Multilayer gallium and aluminum doped ZnO (GZO/AZO) films were fabricated by alternative deposition of Ga-doped zinc oxide(GZO) and Al-doped zinc oxide(AZO) thin film by using pulsed laser deposition(PLD) process. The electrical and optical properties of these GZO/AZO thin films were investigated and compared with those of GZO and AZO thin films. The GZO/AZO GZO/AZO thin films linearly decreases with increasing the Al ratio.

  8. Room temperature radio-frequency plasma-enhanced pulsed laser deposition of ZnO thin films

    Science.gov (United States)

    Huang, S.-H.; Chou, Y.-C.; Chou, C.-M.; Hsiao, V. K. S.

    2013-02-01

    In this study, we compared the crystalline structures, optical properties, and surface morphologies of ZnO thin films deposited on silicon and glass substrates by conventional pulsed laser deposition (PLD) and radio-frequency (RF) plasma-enhanced PLD (RF-PEPLD). The depositions were performed at room temperature under 30-100 mTorr pressure conditions. The RF-PEPLD process was found to have deposited a ZnO structure with preferred (0 0 2) c-axis orientation at a higher deposition rate; however, the RF-PEPLD process generated more defects in the thin films. The application of oxygen pressure to the RF-PEPLD process reduced defects effectively and also increased the deposition rate.

  9. Tailoring Multilayered BiVO4 Photoanodes by Pulsed Laser Deposition for Water Splitting.

    Science.gov (United States)

    Murcia-López, Sebastián; Fàbrega, Cristian; Monllor-Satoca, Damián; Hernández-Alonso, María D; Penelas-Pérez, Germán; Morata, Alex; Morante, Juan R; Andreu, Teresa

    2016-02-17

    Pulsed laser deposition (PLD) is proposed as promising technique for the fabrication of multilayered BiVO4-based photoanodes. For this purpose, bare BiVO4 films and two heterojunctions, BiVO4/SnO2 and BiVO4/WO3/SnO2, have been prepared using consecutive ablation of assorted targets in a single batch. The ease, high versatility and usefulness of this technique in engineering the internal configuration of the photoanode with stoichiometric target-to-substrate transfer are demonstrated. The obtained photocurrent densities are among the highest reported values for undoped BiVO4 without oxygen evolution catalysts (OEC). A detailed analysis of the influence of SnO2 and WO3 layers on the charge transport properties because of the changes at the internal FTO/semiconductor interface is performed through transient photocurrent measurements (TPC), showing that the BiVO4/WO3/SnO2 heterostructure attains a significant decrease in the internal losses and reaches high photocurrent values. This study is expected to open the door to the fabrication of other systems based on ternary (or even more complex) metal oxides as photoanodes for water splitting, which is a promising alternative for obtaining materials able to fulfill the different requierements in the development of more efficient systems for this process.

  10. Plasma interactions determine the composition in pulsed laser deposited thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jikun; Stender, Dieter; Conder, Kazimierz; Wokaun, Alexander; Schneider, Christof W.; Lippert, Thomas, E-mail: thomas.lippert@psi.ch [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Döbeli, Max [Laboratory of Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland)

    2014-09-15

    Plasma chemistry and scattering strongly affect the congruent, elemental transfer during pulsed laser deposition of target metal species in an oxygen atmosphere. Studying the plasma properties of La{sub 0.6}Sr{sub 0.4}MnO{sub 3}, we demonstrate for as grown La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} films that a congruent transfer of metallic species is achieved in two pressure windows: ∼10{sup −3} mbar and ∼2 × 10{sup −1} mbar. In the intermediate pressure range, La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} becomes cation deficient and simultaneously almost fully stoichiometric in oxygen. Important for thin film growth is the presence of negative atomic oxygen and under which conditions positive metal-oxygen ions are created in the plasma. This insight into the plasma chemistry shows why the pressure window to obtain films with a desired composition and crystalline structure is narrow and requires a careful adjustment of the process parameters.

  11. Pulsed laser deposited Al-doped ZnO thin films for optical applications

    Directory of Open Access Journals (Sweden)

    Gurpreet Kaur

    2015-02-01

    Full Text Available Highly transparent and conducting Al-doped ZnO (Al:ZnO thin films were grown on glass substrates using pulsed laser deposition technique. The profound effect of film thickness on the structural, optical and electrical properties of Al:ZnO thin films was observed. The X-ray diffraction depicts c-axis, plane (002 oriented thin films with hexagonal wurtzite crystal structure. Al-doping in ZnO introduces a compressive stress in the films which increase with the film thickness. AFM images reveal the columnar grain formation with low surface roughness. The versatile optical properties of Al:ZnO thin films are important for applications such as transparent electromagnetic interference (EMI shielding materials and solar cells. The obtained optical band gap (3.2–3.08 eV was found to be less than pure ZnO (3.37 eV films. The lowering in the band gap in Al:ZnO thin films could be attributed to band edge bending phenomena. The photoluminescence spectra gives sharp visible emission peaks, enables Al:ZnO thin films for light emitting devices (LEDs applications. The current–voltage (I–V measurements show the ohmic behavior of the films with resistivity (ρ~10−3 Ω cm.

  12. Reproducibility and off-stoichiometry issues in nickelate thin films grown by pulsed laser deposition

    Science.gov (United States)

    Preziosi, Daniele; Sander, Anke; Barthélémy, Agnès; Bibes, Manuel

    2017-01-01

    Rare-earth nickelates are strongly correlated oxides displaying a metal-to-insulator transition at a temperature tunable by the rare-earth ionic radius. In PrNiO3 and NdNiO3, the transition is very sharp and shows an hysteretic behavior akin to a first-order transition. Both the temperature at which the transition occurs and the associated resistivity change are extremely sensitive to doping and therefore to off-stoichiometry issues that may arise during thin film growth. Here we report that strong deviations in the transport properties of NdNiO3 films can arise in films grown consecutively under nominally identical conditions by pulsed laser deposition; some samples show a well-developed transition with a resistivity change of up to five orders of magnitude while others are metallic down to low temperatures. Through a detailed analysis of in-situ X-ray photoelectron spectroscopy data, we relate this behavior to large levels of cationic off-stoichoimetry that also translate in changes in the Ni valence and bandwidth. Finally, we demonstrate that this lack of reproducibility can be remarkably alleviated by using single-phase NdNiO3 targets.

  13. Reinforced Pulsed Laser-Deposited Hydroxyapatite Coating on 316 Stainless Steel

    Science.gov (United States)

    Bajpai, Shubhra; Gupta, Ankur; Pradhan, Siddhartha Kumar; Mandal, Tapendu; Balani, Kantesh

    2014-10-01

    Hydroxyapatite (HA) is a widely used bioceramic known for its chemical similarity with that of bone and teeth (Ca/P ratio of 1.67). But, owing to its extreme brittleness, α-Al2O3 is reinforced with HA and processed as a coating via pulsed laser deposition (PLD). Reinforcement of α-Al2O3 (50 wt.%) in HA via PLD on 316L steel substrate has shown modulus increase by 4% and hardness increase by 78%, and an improved adhesion strength of 14.2 N (improvement by 118%). Micro-scratching has shown an increase in the coefficient-of-friction from 0.05 (pure HA) to 0.17 (with 50 wt.% Al2O3) with enhancement in the crack propagation resistance (CPR) up to 4.5 times. Strong adherence of PLD HA-Al2O3 coatings (~4.5 times than that of HA coating) is attributed to efficient release of stored tensile strain energy (~17 × 10-3 J/m2) in HA-Al2O3 composites, making it a potential damage-tolerant bone-replacement surface coating.

  14. Growth evolution of AlN films on silicon (111) substrates by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haiyan; Wang, Wenliang; Yang, Weijia; Zhou, Shizhong; Lin, Zhiting [State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641 (China); Li, Guoqiang, E-mail: msgli@scut.edu.cn [State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641 (China); Department of Electronic Materials, South China University of Technology, Guangzhou 510641 (China)

    2015-05-14

    AlN films with various thicknesses have been grown on Si(111) substrates by pulsed laser deposition (PLD). The surface morphology and structural property of the as-grown AlN films have been investigated carefully to comprehensively explore the epitaxial behavior. The ∼2 nm-thick AlN film initially grown on Si substrate exhibits an atomically flat surface with a root-mean-square surface roughness of 0.23 nm. As the thickness increases, AlN grains gradually grow larger, causing a relatively rough surface. The surface morphology of ∼120 nm-thick AlN film indicates that AlN islands coalesce together and eventually form AlN layers. The decreasing growth rate from 240 to 180 nm/h is a direct evidence that the growth mode of AlN films grown on Si substrates by PLD changes from the islands growth to the layer growth. The evolution of AlN films throughout the growth is studied deeply, and its corresponding growth mechanism is hence proposed. These results are instructional for the growth of high-quality nitride films on Si substrates by PLD, and of great interest for the fabrication of AlN-based devices.

  15. How to obtain a magnetic hard-soft architecture by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fix, T; Trassin, M; Hassan, R Sayed; Schmerber, G; Viart, N; Meny, C; Colis, S; Dinia, A [Institut de Physique et Chimie des Materiaux de Strasbourg (IPCMS), Unite Mixte de Recherche 7504 du Centre National de la Recherche Scientifique (CNRS), Universite Louis Pasteur-Ecole Europeenne de Chimie, Polymeres et Materiaux de Strasbourg - ULP-ECPM, 23 rue du Loess, BP43 F-67034 Strasbourg (France)

    2007-12-12

    In spin valve type systems, one ferromagnetic electrode must be magnetically hard to act as a reference layer while the other electrode must be magnetically soft to act as a sensor or storage layer. This magnetic hard-soft architecture can usually be obtained by four different methods: the use of two ferromagnets with different coercive fields (here CoFe{sub 2} and Ni{sub 80}Fe{sub 20}), the use of an underlayer enhancing the coercive field of one of the two ferromagnets (here Ta and Ru), the use of a ferromagnet coupled to a ferrimagnet or antiferromagnet (here NiO/CoFe{sub 2} and CoFe{sub 2}O{sub 4}/CoFe{sub 2}), or the use of an artificial antiferromagnet (here CoFe{sub 2}/Ru/CoFe{sub 2}). We show that at least the first and the third methods seem to work with pulsed laser deposition in the thermodynamic conditions used.

  16. Low-field microwave absorption in pulse laser deposited FeSi thin film

    Energy Technology Data Exchange (ETDEWEB)

    Gavi, H. [Department of Physics, SARCHI Chair in Carbon Technology and Materials, Institute of Applied Materials, University of Pretoria, Pretoria 0028 (South Africa); Ngom, B.D. [Groupe d Laboratoires de Physique des Solid et des Materiaux, Faculte deSciences et Techniques, Universite Cheikh Anta de Dakar, BP 25114 Dakar-Fann, Daka 16996 (Senegal); Institut National de la Recherche Scientifique Centre-Energie Materiaux, Telecommunications 1650, Boulevard Lionel Boulet Varennes (Quebec), Canada J3X 1S2 (Canada); Beye, A.C. [Groupe d Laboratoires de Physique des Solid et des Materiaux, Faculte deSciences et Techniques, Universite Cheikh Anta de Dakar, BP 25114 Dakar-Fann, Daka 16996 (Senegal); Strydom, A.M. [Department of Physics, University of Johannesburg, Johannesburg 2006 (South Africa); Srinivasu, V.V., E-mail: vallavs@unisa.ac.za [Department of Physics, University of South Africa, Pretoria 0003 (South Africa); Chaker, M. [Institut National de la Recherche Scientifique Centre-Energie Materiaux, Telecommunications 1650, Boulevard Lionel Boulet Varennes (Quebec), Canada J3X 1S2 (Canada); Manyala, N., E-mail: ncholu.manyala@up.ac.za [Department of Physics, SARCHI Chair in Carbon Technology and Materials, Institute of Applied Materials, University of Pretoria, Pretoria 0028 (South Africa)

    2012-03-15

    Low field microwave absorption (LFMA) measurements at 9.4 GHz (X-band), were carried out on pulse laser deposited (PLD) polycrystalline B20 cubic structure FeSi thin film grown on Si (111) substrate. The LFMA properties of the films were investigated as a function of DC field, temperature, microwave power and the orientation of DC field with respect to the film surface. The LFMA signal is very strong when the DC field is parallel to the film surface and vanishes at higher angles. The LFMA signal strength increases as the microwave power is increased. The LFMA signal disappears around 340 K, which can be attributed to the disappearance of ferromagnetic state well above room temperature in these films. We believe that domain structure evolution in low fields, which in turn modifies the low field permeability as well as the anisotropy, could be the origin of the LFMA observed in these films. The observation of LFMA opens the possibility of the FeSi films to be used as low magnetic field sensors in the microwave and rf frequency regions. - Highlights: Black-Right-Pointing-Pointer B20 crystalline FeSi thin film shows low field microwave absorption. Black-Right-Pointing-Pointer Usual ferromagnic resonance typical of magnetic materials is observed in FeSi film. Black-Right-Pointing-Pointer FeSi film can be used for low magnetic field sensors.

  17. Pulsed-laser deposition of crystalline cobalt ferrite thin films at lower temperatures

    Science.gov (United States)

    Jiles, David; Raghunathan, Arun; Nlebedim, Ikenna; Snyder, John

    2010-03-01

    Cobalt ferrite thin films have been proposed for various engineering applications due to their exceptional magnetic, magnetoelastic, magnetotransport, magnetooptical properties. In this research, cobalt ferrite thin films were grown on SiO2/Si(100) substrates using pulsed-laser deposition (PLD) technique at substrate temperatures ranging from 250 C to 600 C. It has been shown in this study, that polycrystalline films with (111)-preferred orientation can be prepared at substrate temperatures as low as 250 C, as opposed to a report of optimum 600 C substrate temperature [1]. Thermal expansion mismatch between the film and substrate was found to have a substantial effect on the magnetic properties of the cobalt ferrite films, due to the large magnetoelastic coupling of cobalt ferrite. The growth of crystalline cobalt ferrite films at such low temperatures indicates the potential to use cobalt ferrite for MEMS devices and sensor applications [2] including integration with a wider range of multilayered device structures. This research was supported by the UK EPSRC (EP/D057094) and the US NSF (DMR-0402716). [1] J. Zhou et. al, Applied Surface Sciences, 253 (2007), p. 7456. [2] J. A. Paulsen et. al., Journal of Applied Physics, 97 (2005), p. 044502.

  18. Structural and magnetic properties of pulsed laser deposited Fe–SiC thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Mukesh [Nanoscience Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee, UK 247 667 (India); Chandra, Ramesh, E-mail: ramesfic@iitr.ac.in [Nanoscience Laboratory, Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee, UK 247 667 (India); Goyat, Manjeet S. [University of Petroleum & Energy Studies, Dehradun, Uttarakhand 248007 (India); Mishra, Raghwesh; Tiwari, Rajesh K.; Saxena, A.K. [Applied Chemistry Division, Defence Materials & Stores Research & Development Establishment (DMSRDE), GT Road, Kanpur, UP 208013 (India)

    2015-03-31

    Structural and magnetic properties of Fe–SiC thin films have been studied. The Fe–SiC thin films were fabricated by pulsed laser deposition on Si (100) substrate and isochronally annealed at 1073 K and 1273 K in argon atmosphere for 2.5 h. The crystalline ordering of SiC into β-SiC phase and growths of other phases like Fe{sub 3}Si, SiO{sub 2} and FeSiO{sub 3} during annealing were investigated by X-ray diffraction and X-ray photoelectron spectroscopy measurements. The morphology of thin films was changed from voided structure to dense pyramidal-like structure due to annealing. A continuous decrease in the saturation magnetization and non-monotonic change in coercivity of Fe–SiC thin films were observed with increase in annealing temperature. - Highlights: • Structural and magnetic properties of Fe–SiC thin films have been studied. • Crystalline ordering of SiC into β-SiC phase was obtained at T ≥ 800 °C. • Annealed Fe–SiC thin films show ferromagnetic hysteresis at room temperature. • Coercivity was found to be dependent on the annealing temperature.

  19. Dynamic Scaling and Island Growth Kinetics in Pulsed Laser Deposition of SrTiO3

    Science.gov (United States)

    Eres, Gyula; Tischler, J. Z.; Rouleau, C. M.; Lee, Ho Nyung; Christen, H. M.; Zschack, P.; Larson, B. C.

    2016-11-01

    We use real-time diffuse surface x-ray diffraction to probe the evolution of island size distributions and its effects on surface smoothing in pulsed laser deposition (PLD) of SrTiO3 . We show that the island size evolution obeys dynamic scaling and two distinct regimes of island growth kinetics. Our data show that PLD film growth can persist without roughening despite thermally driven Ostwald ripening, the main mechanism for surface smoothing, being shut down. The absence of roughening is concomitant with decreasing island density, contradicting the prevailing view that increasing island density is the key to surface smoothing in PLD. We also report a previously unobserved crossover from diffusion-limited to attachment-limited island growth that reveals the influence of nonequilibrium atomic level surface transport processes on the growth modes in PLD. We show by direct measurements that attachment-limited island growth is the dominant process in PLD that creates step flowlike behavior or quasistep flow as PLD "self-organizes" local step flow on a length scale consistent with the substrate temperature and PLD parameters.

  20. Fabrication of multilayer Laue lenses by a combination of pulsed laser deposition and focused ion beam.

    Science.gov (United States)

    Liese, Tobias; Radisch, Volker; Krebs, Hans-Ulrich

    2010-07-01

    X-ray diffractive techniques using Fresnel zone plate lenses of various forms are of great technical interest because of their ability to form images at very high spatial resolution, but the zone plates are unfortunately very hard to produce by lithography. Alternatively, multilayer Laue lenses (MLLs) and multilayer zone plates are used due to the higher and easily adjustable aspect ratio necessary for different wavelengths. In this paper, the fabrication of a MLL by a combination of pulsed laser deposition and focused ion beam machining is described. All steps of the production of a Ti/ZrO(2) microlens test structure with focal length of 220 microm (for a wavelength of 2.88 nm in the "water window" regime) are explained in detail. It is shown that this combination of two powerful techniques is very effective for the fabrication of MLL. All steps can be done in a very precise and controlled way without introducing damage to the grown multilayer structures.

  1. Pulsed laser annealing of highly doped Ge:Sb layers deposited on different substrates

    Science.gov (United States)

    Batalov, R. I.; Bayazitov, R. M.; Faizrakhmanov, I. A.; Lyadov, N. M.; Shustov, V. A.; Ivlev, G. D.

    2016-10-01

    Germanium (Ge) is a promising material for micro- and optoelectronics to produce high speed field-effect transistors, photodetectors, light-emitting diodes and lasers. For such applications tensile-strained and/or highly n-doped Ge layers are needed. The authors have performed the formation of such layers by ion-beam sputtering of composite Sb/Ge target, deposition of thin amorphous Ge:Sb films (~200 nm thick) on different substrates (c-Si, c-Al2O3, α-SiO2) followed by pulsed laser annealing (PLA) for their crystallization and Sb dopant activation. Structural, electrical and optical characterization of Ge:Sb films was carried out using scanning electron microscopy, x-ray diffraction, micro-Raman spectroscopy, secondary ion mass spectrometry methods and by measuring sheet resistance, carrier concentration and photoluminescence. The obtained polycrystalline n-Ge:Sb layers (N Sb ~ 1 at.%) are characterized by increased values of tensile strain (up to 1%) and homogenious Sb dopant distribution within layer thickness. The electrical measurements at 300 K revealed the low sheet resistance (up to 40 Ω/□) and extremely high electron concentration (up to 5.5  ×  1020 cm-3) in Ge:Sb/SiO2 samples that indicated full electrical activation of Sb dopant on SiO2 substrate. The increased values of tensile strain and electron concentration of Ge:Sb films on α-SiO2 are explained by low values of thermal conductivity and thermal expansion coefficients of quartz substrate.

  2. Study of Doped ZnO Films Synthesized by Combining Vapor Gases and Pulsed Laser Deposition

    Science.gov (United States)

    Zhu, Shen; Su, Ching-Hua; Lehoczky, Sandor L.; George, M. A.

    2000-01-01

    The properties and structure of the ZnO material are similar to those of the GaN. Since an excitonic binding energy of ZnO is about 60 meV, it has strong potential for excitonic lasing at the room temperature. This makes synthesizing ZnO films for applications attractive. However, there are several hurdles in fabricating electro-optical devices from ZnO. One of those is in growing doped p-type ZnO films. Although techniques have been developed for the doping of both p-type and n-type ZnO, this remains an area that can be improved. In this presentation, we will report the experimental results of using both thermal vapor and pulsed laser deposition to grow doped ZnO films. The films are deposited on (0001) sapphire, (001) Si and quartz substrates by ablating a ZnO target. The group III and V elements are introduced into the growth chamber using inner gases. Films are characterized by x-ray diffraction, scanning probe microscopy, energy dispersive spectroscopy, Auger electron spectroscopy, and electrical measurements. The full width at half maximum of theta rocking curves for epitaxial films is less than 0.5 deg. In textured films, it rises to several degrees. Film surface morphology reveals an island growth pattern, but the size and density of these islands vary with the composition of the reactive gases. The electrical resistivity also changes with the doped elements. The relationship between the doping elements, gas composition, and film properties will be discussed.

  3. Structural and Electrical Properties of Heteroepitaxial Magnetic Oxide Junction Diode Fabricated by Pulsed Laser Deposition

    Science.gov (United States)

    Li, M. K.; Wong, K. H.

    2010-11-01

    Heteroepitaxial junctions formed by p-type strontium doped lanthanum manganite and n-type cobalt doped titanium dioxide were fabricated on LaAlO3 (100) substrates by pulsed laser deposition. The La0.7Sr0.3MnO3 (LSMO) layers were grown at 650° C and under 150 mTorr ambient oxygen pressure. They showed room temperature ferromagnetism and metallic-like electrical conduction with a resistivity of 0.015 ohm cm at 300 K. The CoxTi1-xO2[x = 0.05 and 0.1] (CTO), which, at anatase phase, was reported as a wide-band-gap dilute magnetic semiconductor, was deposited on the LSMO film surface at 600° C with an ambient oxygen pressure of 20 mTorr. The as-grown CTO films exhibited pure anatase crystalline phase and semiconductor-like conduction. Under optimized fabrication conditions the CTO/LSMO junction revealed a heteroepitaxial relationship of (004)CTO‖‖(001)LSMO‖‖(001)LAO. Electrical characterization of these p-n junctions yielded excellent rectifying characteristics with a current rectifying ratio over 1000 at room temperature. The electrical transport across these diodes was dominated by diffusion current at low current (low bias voltage) regime and by recombination current at high current (high bias voltage) regime. Our results have demonstrated an all-oxide spintronic junction diode with good transport property. The simultaneous of electrical and magnetic modulation in a diode junction is therefore potentially realizable.

  4. Pulsed laser deposition of nanostructured Co-B-O thin films as efficient catalyst for hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Jadhav, H., E-mail: jadhav.hs2013@gmail.com [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Singh, A.K. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Patel, N.; Fernandes, R.; Gupta, S.; Kothari, D.C. [Department of Physics and National Centre for Nanosciences & Nanotechnology, University of Mumbai, Vidyanagari, Santacruz (E), Mumbai 400098 (India); Miotello, A. [Dipartimento di Fisica, Università degli Studi di Trento, I-38123 Povo, Trento (Italy); Sinha, S. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2016-11-30

    Highlights: • Pulsed laser deposition was used to deposit Co-B-O film nanocatalyst. • Co-B-O NPs are well separated, stable and immobilized on film surface. • Catalytic H{sub 2} production was studied by hydrolysis of Sodium Borohydride. • Four times higher H{sub 2} production rate was recorded for Co-B-O film than Co-B-O powder. • High particle density, polycrystalline nature and good stability against agglomeration of Co NPs. - Abstract: Nanoparticles assembled Co-B-O thin film catalysts were synthesized by pulsed laser deposition (PLD) technique for hydrolysis of Sodium Borohydride (SBH). Surface morphology of the deposited films was investigated using SEM and TEM, while compositional analysis was studied using XPS. Structural properties of Co-B-O films were examined using XRD and HRTEM. Laser process is able to produce well separated and immobilized Co-B-O NPs on the film surface which act as active centers leading to superior catalytic activity producing hydrogen at a significantly higher rate as compared to bulk powder. Co-B-O thin film catalyst produces hydrogen at a maximum rate of ∼4400 ml min{sup −1} g{sup −1} of catalyst, which is four times higher than powder catalyst. PLD parameters such as laser fluence and substrate-target distance were varied during deposition in order to understand the role of size and density of the immobilized Co-B-O NPs in the catalytic process. Films deposited at 3–5 cm substrate-target distance showed better performance than that deposited at 6 cm, mainly on account of the higher density of active Co-B-O NPs on the films surface. Features such as high particle density, polycrystalline nature of Co NPs and good stability against agglomeration mainly contribute towards the superior catalytic activity of Co-B-O films deposited by PLD.

  5. In situ spectroelectrochemical behaviour of nanocrystalline TiO2 thin films electrode fabricated by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    傅正文; 孔继烈; 秦启宗; 田中群

    1999-01-01

    Nanocrystalline titanium oxide thin films have been successfully deposited on ITO coated glass by pulsed laser ablation of metallic Ti target in O3/O2 ambient gases. The intercalation of Li ions in the anatase TiO2 film electrode is examined by cyclic vohammetry. The electrochromic behaviour of TiO2 electrode is investigated by in-situ visible transmittance measurement, and two absorption bands at 420 and 650 nm are observed. The absorption falling and rising in color changing with excellent revisibility is relative to the insertion and deintercalation processes of Li ion. These resuits suggest that nanocrystalline titanium oxide films fabricated by pulsed laser deposition exhibit excellent spectroelectrochemical property.

  6. Chemical Oxidation of La2CuO4 Epitaxial Thin Films Grown by Pulsed Laser Deposition

    Institute of Scientific and Technical Information of China (English)

    WANG Chun-Chang; YAN Yun-Jie; ZHU Jing

    2007-01-01

    Chemical oxidation is used to induce superconductivity in La2CuO4 expitaxial thin films fabricated by pulsed laser deposition technique. Details about the influence of oxidation time on structural, surface morphology, Raman spectra, and electrical properties have been investigated. The results convince that successful uptake of oxygen occurs in the oxidized films, and the content of the inserted oxygen increases with increasing oxidation interval. The possible mechanism for the excess oxygen insertion into the film is also discussed.

  7. Stress induced magnetic anisotropy of CoFe2O4 thin films using pulsed laser deposition

    NARCIS (Netherlands)

    Pham Duc Thang, P.D.T.; Rijnders, Augustinus J.H.M.; Blank, David H.A.

    2007-01-01

    Cobalt ferrite (CoFe2O4) thin films (E70 nm) were epitaxially grown on TiO2-terminated (0 0 1) SrTiO3 substrates by pulsed laser deposition (PLD). Films with very smooth surface, which follow the terrace of the substrate, were obtained at temperatures below 600 1C. The magnetic properties of CoFe2O4

  8. A nucleation and growth model of silicon nanoparticles produced by pulsed laser deposition via Monte Carlo simulation

    Science.gov (United States)

    Wang, Yinglong; Qin, Aili; Chu, Lizhi; Deng, Zechao; Ding, Xuecheng; Guan, Li

    2017-02-01

    We simulated the nucleation and growth of Si nanoparticles produced by pulse laser deposition using Monte Carlo method at the molecular (microscopic) level. In the model, the mechanism and thermodynamic conditions of nucleation and growth of Si nanoparticles were described. In a real physical scale of target-substrate configuration, the model was used to analyze the average size distribution of Si nanoparticles in argon ambient gas and the calculated results are in agreement with the experimental results.

  9. Growth of poly-crystalline Cu films on Y substrates by picosecond pulsed laser deposition for photocathode applications

    Energy Technology Data Exchange (ETDEWEB)

    Gontad, F. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, 73100 Lecce (Italy); Lorusso, A., E-mail: antonella.lorusso@le.infn.it [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, 73100 Lecce (Italy); Klini, A.; Manousaki, A. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), 100 N. Plastira St., GR 70013 Heraklion, Crete (Greece); Perrone, A. [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi” and Istituto Nazionale di Fisica Nucleare, 73100 Lecce (Italy); Fotakis, C. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), 100 N. Plastira St., GR 70013 Heraklion, Crete (Greece)

    2015-11-01

    In this work, the deposition of Cu thin films on Y substrates for photocathode applications by pulsed laser deposition employing picosecond laser pulses is reported and compared with the use of nanosecond pulses. The influence of power density (6–50 GW/cm{sup 2}) on the ablation of the target material, as well as on the properties of the resulting film, is discussed. The material transfer from the target to the substrate surface was found to be rather efficient, in comparison to nanosecond ablation, leading to the growth of films with high thickness. Scanning electron microscope analysis indicated a quasi-continuous film morphology, at low power density values, becoming granular with increasing power density. The structural investigation, through X-ray diffraction, revealed the poly-crystalline nature of the films, with a preferential growth along the (111) crystallographic orientation of Cu cubic network. Finally, energy-dispersive X-ray spectroscopy showed a low contamination level of the grown films, demonstrating the potential of a PLD technique for the fabrication of Cu/Y patterned structures, with applications in radiofrequency electron gun technology. - Highlights: • Cu thin films were successfully deposited on Y substrates through ultrafast PLD. • The film presents a quasi-continuous morphology. • The use of picosecond pulses increases the film thickness. • The Cu thin films are very adherent to the Y substrate.

  10. Pulsed Laser Deposition of Thin Films for Lasers and Quasi-Phase Matched Devices

    Science.gov (United States)

    2013-01-16

    Optics , waveguides, Lasers 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18, NUMBER OF PAGES 11 19a. NAME OF...and AFRL, concerning PLD research  in general. The  offer has been made  for a current student to visit ARFL, and  interact over  multibeam  PLD

  11. Synthesis of Few-Layer, Large Area Hexagonal-Boron Nitride by Pulsed Laser Deposition (POSTPRINT)

    Science.gov (United States)

    2014-09-01

    by annealing at 1000 °C [16]. This also includes recent reports on the direct CVD growth of h BN on the surface of epitaxial graphene with an ammonia ...C with B:N ratios of approximately one. Nanoscale thicknesses of h BN were synthesized using a high powered CO2 pulsed laser and showed a possibility

  12. Optimisation study of the synthesis of vanadium oxide nanostructures using pulsed laser deposition

    CSIR Research Space (South Africa)

    Masina, BN

    2014-02-01

    Full Text Available Fast imaging plasma plume study have been carried out on vanadium-oxygen plasma generated using 248 nm, 25 ns pulses from an excimer KrF laser under oxygen atmosphere. The plume expansion dynamics of an ablated VO(sub2) target was investigated using...

  13. Structure property relationships of nitride superlattice hard coatings prepared by pulsed laser deposition

    Science.gov (United States)

    Patel, Nitin

    Today, more than 40% of all cutting tools used in machining applications are covered with coatings. Coatings improve wear resistance, increase tool life, enable use at higher speed, and broaden the application range. Superlattices, where thin layers (typically deposited in an alternating fashion, are widely used commercially. Importantly, the hardness value of a superlattice (e.g. TiN/AlN) can significantly exceed the rule of mixture value. Superlattice coatings built from crystallographically dissimilar materials are not widely studied but hold promise for improvements in performance by allowing for both hardness and toughness to be simultaneously optimized. This is what this thesis is concerned with: a structure-property comparison of isostructural superlattices with corresponding non-isostructural superlattices. In order to grow both isostructural and non-isostructural superlattices from the same set of materials, it is necessary to grow monolithic films in different phases. Towards this end, the synthesis of different phases of AlN, (Ti,Al)N, TaN, and TiN was investigated. Films were grown by pulsed laser deposition in two different chambers that had different base pressures to study the effect of background gases on the phases and orientations of the films. Growth of AlN and (Ti,Al)N films is strongly affected in a chamber that had a base pressure of 10-6 Torr, but the films adopt their stable nitride structures in a chamber with the lower base pressure of 10-8 Torr. TaN adopts either the cubic rock salt structure or its stable hexagonal structure, depending on the growth temperature, while TiN grows as rock salt in all conditions. Single crystal epitaxial superlattices were then grown with different compositions, periodicities, and crystallographic orientations to compare the effect of chemistry, nanostructure, and crystallographic texture on hardness. Finally, the structure-property relationships of non-isostructural (cubic/hexagonal) superlattices are

  14. Smooth YBa2Cu3O7-x thin films prepared by pulsed laser deposition in O2/Ar atmosphere

    DEFF Research Database (Denmark)

    Kyhle, Anders; Skov, Johannes; Hjorth, Søren

    1994-01-01

    We report on pulsed laser deposition of YBa2Cu3O7-x in a diluted O2/Ar gas resulting in thin epitaxial films which are almost outgrowth-free. Films were deposited on SrTiO3 or MgO substrates around 800-degrees-C at a total chamber pressure of 1.0 mbar, varying the argon partial pressure from 0 to 0.......6 mbar. The density of boulders and outgrowths usual for laser deposited films varies strongly with Ar pressure: the outgrowth density is reduced from 1.4 x 10(7) to 4.5 x 10(5) cm-2 with increasing Ar partial pressure, maintaining a critical temperature T(c,zero) almost-equal-to 90 K and a transport...... critical current density J(c)(77 K) greater-than-or-equal-to 10(6) A/cm2 by extended oxygenation time during cool down....

  15. Pulsed laser deposition of PbTe under monopulse and multipulse regime

    Science.gov (United States)

    Alvira, F. C.; Cabrera, L. Ponce; Peñaloza Mendoza, Y.; Martinez Ricci, M. L.; Videla, F.

    2017-03-01

    The aim of this paper is to compare PLD technique with monopulse and multipulse nanosecond laser excitation. We show the feasibility of depositing nanometric layers of PbTe employing the regimes already mentioned. Each of the grown layers were characterized by XRD, EDXS, SEM, Spectroscopic Elipsometry, AFM and the thickness was measured by mechanic profilometry. We have conducted comparative experiments to show the advantages and drawbacks of making PLD with mono and multipulse nanosecond laser.

  16. Effect of substrate temperature on microstructural and optical properties of ZnO films grown by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    ZnO thin films were deposited on n-Si (111) at various substrate temperatures by pulsed laser deposition (PLD).X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectrophotometer (FTIR), and scanning electron microscopy (SEM) were used to analyze the structure, morphology, and optical property of the ZnO thin films. An optimal crystallized ZnO thin film was obtained at the substrate temperature of 600℃. A blue shift was found in PL spectra due to size confinement effect as the grain sizes decreased. The surfaces of the ZnO thin films were more planar and compact as the substrate temperature increased.

  17. Pulsed laser deposition of piezoelectric ZnO thin films for bulk acoustic wave devices

    Energy Technology Data Exchange (ETDEWEB)

    Serhane, Rafik, E-mail: rserhane@cdta.dz [Centre for Development of Advanced Technologies, Cité 20 Août 1956, Baba Hassen, BP: 17, DZ-16303 Algiers (Algeria); Abdelli-Messaci, Samira; Lafane, Slimane; Khales, Hammouche; Aouimeur, Walid [Centre for Development of Advanced Technologies, Cité 20 Août 1956, Baba Hassen, BP: 17, DZ-16303 Algiers (Algeria); Hassein-Bey, Abdelkadder [Centre for Development of Advanced Technologies, Cité 20 Août 1956, Baba Hassen, BP: 17, DZ-16303 Algiers (Algeria); Micro and Nano Physics Group, Faculty of Sciences, University Saad Dahlab of Blida (USDB), BP. 270, DZ-09000 Blida (Algeria); Boutkedjirt, Tarek [Equipe de Recherche Physique des Ultrasons, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32, El-Alia, Bab-Ezzouar, DZ-16111 Algiers (Algeria)

    2014-01-01

    Piezoelectric properties of ZnO thin films have been investigated for micro-electro-mechanical systems (MEMS). Wurtzite ZnO structure was prepared on different substrates (Si (1 0 0), Pt (1 1 1)/Ti/SiO{sub 2}/Si and Al (1 1 1)/SiO{sub 2}/Si) at different substrate temperatures (from 100 to 500 °C) by a pulsed laser deposition (PLD) technique. X-ray diffraction (XRD) characterization showed that the ZnO films were highly c-axis (0 0 2) oriented, which is of interest for various piezoelectric applications. Scanning electron microscopy (SEM) showed evidence of honeycomb-like structure on the surface and columnar structure on the cross-section. In the case of ZnO on Al, ZnO exhibited an amorphous phase at the ZnO/Al interface. The XRD measurements indicated that the substrate temperature of 300 °C was the optimum condition to obtain high quality (strongest (0 0 2) peak with the biggest associated grain size) of crystalline ZnO on Pt and on Al and that 400 °C was the optimum one on Si. ZnO on Al exhibits smallest rocking curve width than on Pt, leading to better crystalline quality. The ZnO films were used in bulk acoustic wave (BAW) transducer. Electrical measurements of the input impedance and S-Parameters showed evidence of piezoelectric response. The electromechanical coupling coefficient was evaluated as K{sub eff}{sup 2}=5.09%, with a quality factor Q{sub r} = 1001.4.

  18. Pulsed laser deposition of piezoelectric ZnO thin films for bulk acoustic wave devices

    Science.gov (United States)

    Serhane, Rafik; Abdelli-Messaci, Samira; Lafane, Slimane; Khales, Hammouche; Aouimeur, Walid; Hassein-Bey, Abdelkadder; Boutkedjirt, Tarek

    2014-01-01

    Piezoelectric properties of ZnO thin films have been investigated for micro-electro-mechanical systems (MEMS). Wurtzite ZnO structure was prepared on different substrates (Si (1 0 0), Pt (1 1 1)/Ti/SiO2/Si and Al (1 1 1)/SiO2/Si) at different substrate temperatures (from 100 to 500 °C) by a pulsed laser deposition (PLD) technique. X-ray diffraction (XRD) characterization showed that the ZnO films were highly c-axis (0 0 2) oriented, which is of interest for various piezoelectric applications. Scanning electron microscopy (SEM) showed evidence of honeycomb-like structure on the surface and columnar structure on the cross-section. In the case of ZnO on Al, ZnO exhibited an amorphous phase at the ZnO/Al interface. The XRD measurements indicated that the substrate temperature of 300 °C was the optimum condition to obtain high quality (strongest (0 0 2) peak with the biggest associated grain size) of crystalline ZnO on Pt and on Al and that 400 °C was the optimum one on Si. ZnO on Al exhibits smallest rocking curve width than on Pt, leading to better crystalline quality. The ZnO films were used in bulk acoustic wave (BAW) transducer. Electrical measurements of the input impedance and S-Parameters showed evidence of piezoelectric response. The electromechanical coupling coefficient was evaluated as Keff2    =    5 .0 9 %, with a quality factor Qr = 1001.4.

  19. Structural, optical and magnetic properties of pulsed laser deposited Co-doped ZnO films

    Energy Technology Data Exchange (ETDEWEB)

    Karzazi, O., E-mail: ouiame_karzazi@hotmail.fr [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); LPS, Physics Department, Faculty of Sciences, BP 1796, Fes (Morocco); Sekhar, K.C. [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); El Amiri, A. [LPTA, Université Hassan II-Casablanca, Faculté des Sciences, B.P. 5366, Maârif (Morocco); Hlil, E.K. [Institut Néel, CNRS, Université J. Fourier, BP 166, 38042 Grenoble (France); Conde, O. [Departamento de Física, Faculdade de Ciências, Universidade de Lisboa and CeFEMA, Campo Grande, 1749-016 Lisboa (Portugal); Levichev, S. [Research Institute for Chemistry, Nizhni Novgorod State University, 603950 Nizhni Novgorod (Russian Federation); Agostinho Moreira, J. [IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007, Porto (Portugal); Chahboun, A. [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); FST Tanger, Physics Department, BP 416, Tangier (Morocco); Almeida, A. [IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007, Porto (Portugal); Gomes, M.J.M. [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2015-12-01

    Zn{sub 1−x}Co{sub x}O films with different Co concentrations (with x=0.00, 0.10, 0.15, and 0.30) were grown by pulsed laser deposition (PLD) technique. The structural and optical properties of the films were investigated by grazing incidence X-ray diffraction (GIXRD), Raman spectroscopy and photoluminescence (PL). The magnetic properties were measured by conventional magnetometry using a SQUID and simulated by ab-initio calculations using Korring–Khon–Rostoker (KKR) method combined with coherent potential approximation (CPA). The effect of Co-doping on the GIXRD and Raman peaks positions, shape and intensity is discussed. PL studies demonstrate that Co-doping induces a decrease of the bandgap energy and quenching of the UV emission. They also suggest the presence of Zn interstitials when x≥0.15. The 10% Co-doped ZnO film shows ferromagnetism at 390 K with a spontaneous magnetic moment ≈4×10{sup −5} emu and coercive field ≈0.17 kOe. The origin of ferromagnetism is explained based on the calculations using KKR method. - Highlights: • Zn{sub 1−x}Co{sub x}O films (x=0.00, 0.10, 0.15, and 0.30) were grown by (PLD) technique. • Zn{sub 0.9}Co{sub 0.1}O film shows ferromagnetism above room temperature. • The origin of ferromagnetism behavior is attributed to the p-d hybridization. • Co-doping induces a decrease of the bandgap energy of the films.

  20. Electronic properties of high-temperature superconducting thin films grown by pulsed laser deposition

    Science.gov (United States)

    Abrecht, M.; Ariosa, Daniel; Cloetta, D.; Margaritondo, Giorgio; Pavuna, Davor

    2002-11-01

    We use a pulsed laser deposition (PLD) setup to grow ultra-thin films of high temperature superconductors (HTSC) and transfer them in-situ into a photoemission chamber. Photoemission measurements on such films allow us to study non-cleavable materials, but can also give insights into aspects never measured before, like the influence of strain on the low energy electronic structure. Systematic studies of many different materials grown as films showed that Bi2Sr2CaCu2O8+x, Bi2Sr2Cu1O6+x, Bi2Sr2Ca2Cu3O10+x and La2-xSrxCuO4 films exhibit a conductor-like Fermi edge, but materials containing chains (such as YBa2Cu3O7-x) are prone to very rapid surface degradation, possibly related to critical oxygen loss at the surface. Among HTSC materials, La2-xSrxCuO4 is extremely interesting because of its rather simple structure and the fact that its critical temperature Tc can be enhanced by epitaxial strain. Here we present our first high resolution angular resolved photoemission spectroscopy (ARPES) results on 8 unit-cell thin La2-xSrxCuO4 films on SrLaAlO4 [001] substrates. Due to the lattice mismatch, such films are compressed in the copper oxygen planes and expanded in the c-axis direction. Results show a surprisingly modified Fermi surface compared to the one of non-strained samples.

  1. Improved properties of pulsed laser deposited YBaCuO on NdGaO3 using CeO2 template layers

    NARCIS (Netherlands)

    Blank, Dave H.A.; Rijnders, A.J.H.M.; Roesthuis, F.J.G.; Ouden, den G.; Rogalla, H.

    1996-01-01

    NdGaO3 (NGO) is, due to its low loss characteristics, a favourite substrate for high frequency applications [1]. However, problems occur when trying to deposit high quality YBaCuO layers on top of it. The optimum deposition temperature during pulsed laser deposition to obtain high Tc, high critical

  2. Pulsed laser deposition from ZnS and Cu2SnS3 mulitcomponent targets

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt; Cazzaniga, Andrea Carlo; Canulescu, Stela;

    2015-01-01

    Thin films of ZnS and Cu2SnS3have been produced by pulsed laser deposition (PLD), the latter for the firsttime. The effect of fluence and deposition temperature on the structure and the transmission spectrumas well as the deposition rate has been investigated, as has the stoichiometry of the film...

  3. Oxygen content of YBaCuO thin films during growth by pulsed laser deposition

    NARCIS (Netherlands)

    Garcia lopez, F.J.; Garcia lopez, J.J.; Blank, David H.A.; Rogalla, Horst

    1998-01-01

    The oxidation ability of the laser plasma plume during in situ formation of YBa2Cu3O6+x (YBaCuO) thin films has been studied as a function of the deposition conditions. A quenching technique has been used immediately after termination of growth to avoid any oxygen in or out-diffusion during the

  4. Parametric study of self-forming ZnO Nanowall network with honeycomb structure by Pulsed Laser Deposition

    KAUST Repository

    El Zein, B.

    2014-02-01

    The successful synthesis of catalyst free zinc oxide (ZnO) Nanowall networks with honeycomb like structure by Pulsed Laser Deposition (PLD) is demonstrated in this paper. The synthesis was conducted directly on Silicon (Si) (1 0 0) and Glass-ITO substrates without the intermediate of metal catalyst, template or chemical etching. Kinetic of growth and effects of gas pressure and substrate temperature were studied by depositing ZnO films on P type Si (1 0 0) substrates with different deposition parameters. The optimized growth parameters were found as: 10 mTorr oxygen pressure, 600 C substrate temperature, and deposition duration equal or higher than 10 min. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Photoluminescence (PL) measurements were used to investigate structural, microstructural and optical properties of ZnO Nanowall networks produced. They exhibit a non-uniform size high quality honeycomb structure with low deep level defects. © 2013 Elsevier B.V.

  5. Thermal effects on structure and photoluminescence properties of diamond-like carbon films prepared by pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    CHEN Da; LI Qing-shan; WANG Jing-jing; ZHENG Xue-gang

    2006-01-01

    Un-hydrogenated Diamond-like Carbon (DLC) films were prepared by pulsed laser deposition technique at different substrate temperature.The Raman spectra,the absorption and the photoluminescence spectra were measured.The dependence of structure and photoluminescence properties on deposition temperature were studied in detail.The experimental results indicate that the sp2 sites form small clusters that consist of both olefinic chains and aromatic ring groups within the sp3 matrix.With raising deposition temperature,the optical band gaps increase from 1.87 to 2.85 eV.The main band of photoluminescence centered at around 700nm shifts to short wavelength,and the intensity of this band increases.The photoluminescence can be attributed to carrier localization within an increasing sp2 clusters.It was clarified that the DLC films are ordered with increasing deposition temperature.

  6. Kinetic Monte Carlo simulation of growth of BaTiO3 thin film via pulsed laser deposition

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Considering the characteristics of perovskite structure, a kinetic Monte Carlo(KMC) model, in which Bom-Mayer-Huggins(BMH) potential was introduced to calculate the interatomic interactions and the bonding ratio was defined to reflect the crystallinity, was developed to simulate the growth of BaTiO3 thin film via pulsed laser deposition(PLD). Not only the atoms deposition and adatoms diffusion, but also the bonding of adatoms were considered distinguishing with the traditional algorithm. The effects of substrate temperature, laser pulse repetition rate and incident kinetic energy on BaTiO3 thin film growth were investigated at submonolayer regime. The results show that the island density decreases and the bonding ratio increases with the increase of substrate temperature from 700 to 850 K. With the laser pulse repetition rate increasing, the island density decreases while the bonding ratio increases. With the incident kinetic energy increasing, the island density decreases except 6.2 eV<Ek<9.6 eV, and the bonding ratio increases at Ek<9.6 eV. The simulation results were discussed compared with the previous experimental results.

  7. Double-beam pulsed laser deposition for the growth of Al-incorporated ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, L. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, AP 70-186, C.P. 04510 México D.F., México (Mexico); Sánchez-Aké, C., E-mail: citlali.sanchez@ccadet.unam.mx [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, AP 70-186, C.P. 04510 México D.F., México (Mexico); Bizarro, M. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-186, C.P. 04510 México D.F., México (Mexico)

    2014-05-01

    Pulsed laser deposition in a delayed-double beam configuration is used to incorporate in situ Al in ZnO thin films. In this configuration, two synchronized pulsed-laser beams are employed to ablate independently a ZnO and an Al target. We investigated the effects of relative time delay of plasma plumes on the composition of the films with the aim of evaluating the performance of this technique to produce doped materials. Relative delay between plumes was found to control the incorporation of Al in the film in the range from 14% to 30%. However, to produce low impurity concentration of Al-doped ZnO (with Al incorporation less than 2%) the fluence used to produce the plasmas has more influence over the film composition than the relative plume delay. The minimum incorporation of Al corresponded to a relative delay of 0 μs, due to the interaction between plumes during their expansion.

  8. Self-organized single crystal mixed magnetite/cobalt ferrite films grown by infrared pulsed-laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Figuera, Juan de la, E-mail: juan.delafiguera@iqfr.csic.es [Instituto de Química Física “Rocasolano”, CSIC, Madrid E-28006 (Spain); Quesada, Adrián [Instituto de Cerámica y Vidrio, CSIC, Madrid E-28049 (Spain); Martín-García, Laura; Sanz, Mikel; Oujja, Mohamed; Rebollar, Esther; Castillejo, Marta [Instituto de Química Física “Rocasolano”, CSIC, Madrid E-28006 (Spain); Prieto, Pilar; Muñoz-Martín, Ángel [Universidad Autónoma de Madrid, E-28049 (Spain); Aballe, Lucía [Alba Synchrotron Light Facility, CELLS, Barcelona (Spain); Marco, José F. [Instituto de Química Física “Rocasolano”, CSIC, Madrid E-28006 (Spain)

    2015-12-30

    Highlights: • Infrared pulsed deposition is used to grow single crystal mixed magnetite-cobalt ferrite films. • Distinct topography with two mound types on the surface of the film. • Suggested origin of segregation into two phases is oxygen deficiency during growth. • Mössbauer is required to quantify the two components. - Abstract: We have grown mixed magnetite/cobalt ferrite epitaxial films on SrTiO{sub 3} by infrared pulsed-laser deposition. Diffraction experiments indicate epitaxial growth with a relaxed lattice spacing. The films are flat with two distinct island types: nanometric rectangular mounds in two perpendicular orientations, and larger square islands, attributed to the two main components of the film as determined by Mössbauer spectroscopy. The origin of the segregation is suggested to be the oxygen-deficiency during growth.

  9. Tailoring out-of-plane magnetic properties of pulsed laser deposited FePt thin films by changing laser energy fluence

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying; Tan, T.L.; Tan, K.S.; Lee, P. [NSSE, NIE, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore); Liu, Hai; Yadian, Boluo; Hu, Ge; Huang, Yizhong; Ramanujan, R.V. [School of Material Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Rawat, R.S., E-mail: rajdeep.rawat@nie.edu.sg [NSSE, NIE, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616 (Singapore)

    2014-10-01

    Highlights: • Laser energy fluence (LEF) effect on composition, microstructure and magnetism. • Enhancing out-of-plane magnetic properties by tailoring LEF on target surface. • Higher LEF results in more energetic plasma species causing vacancy defects. • Formation of vacancy defect in FePt thin films leads to improved magnetic properties. • Best out-of-plane magnetic properties are achieved with medium LEF. - Abstract: Magnetic properties of pulsed laser deposited (PLD) FePt thin films are investigated at three different laser energy fluences of 51, 136 and 182 J/cm{sup 2}. Deposition at lower laser energy fluence (51 J/cm{sup 2}) yields softer out-of-plane coercivity (≤0.4 kG), whereas deposition at higher laser energy fluence (136 and 182 J/cm{sup 2}) results in harder out-of-plane coercivity (≥5.0 kG). The improved coercivity is found to be attributed to the formation of vacancy defects in thin films, which is indicated by stress change from tensile to compressive form with increasing laser energy fluence. Maximum out-of-plane saturated magnetization of 615 emu/cm{sup 3} and remanent squareness ratio of 0.88 are achieved for 16 nm thick FePt thin films deposited at moderate laser energy fluence of 136 J/cm{sup 2}, making them suitable for high density perpendicular data storage applications.

  10. Enhancement of photoconversion efficiency in dye-sensitized solar cells exploiting pulsed laser deposited niobium pentoxide blocking layers

    Energy Technology Data Exchange (ETDEWEB)

    Sacco, Adriano, E-mail: adriano.sacco@iit.it [Center for Space Human Robotics@PoliTo, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Di Bella, Maurizio Salvatore [Department of Energy, Information Engineering and Mathematical Models (DEIM), Thin Films Laboratory, Università di Palermo, Viale delle Scienze, Building 9, 90128 Palermo (Italy); Gerosa, Matteo [Center for Space Human Robotics@PoliTo, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Applied Science and Technology Department (DISAT), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Chiodoni, Angelica; Bianco, Stefano [Center for Space Human Robotics@PoliTo, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Mosca, Mauro; Macaluso, Roberto; Calì, Claudio [Department of Energy, Information Engineering and Mathematical Models (DEIM), Thin Films Laboratory, Università di Palermo, Viale delle Scienze, Building 9, 90128 Palermo (Italy); Pirri, Candido Fabrizio [Center for Space Human Robotics@PoliTo, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Applied Science and Technology Department (DISAT), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2015-01-01

    Among all the photovoltaic technologies developed so far, dye-sensitized solar cells are considered as a promising alternative to the expensive and environmentally unfriendly crystalline silicon-based solar cells. One of the possible strategies employed to increase their photovoltaic efficiency is to reduce the charge recombination at the cell conductive substrate through the use of a compact blocking layer. In this paper, we report on the fabrication and characterization of dye-sensitized solar cells employing niobium pentoxide (Nb{sub 2}O{sub 5}) thin film blocking layer deposited through the pulsed laser deposition technique on conductive substrates. The careful selection of the optimal film thickness led to a 30% enhancement of the photoconversion efficiency with respect to reference cells fabricated without blocking layer. Open circuit voltage decay and electrochemical impedance spectroscopy techniques proved that the effective suppression of the charge recombination occurring at the substrate/electrolyte interface represents the main reason for the improvement of the photovoltaic efficiency. - Highlights: • Niobium pentoxide thin films were fabricated through pulsed laser deposition. • The deposited films were employed as recombination blocking layer in DSCs. • The selection of the optimal film thickness led to the enhancement of the efficiency.

  11. Formation of hydroxyapatite coating on titanium at 200°C through pulsed laser deposition followed by hydrothermal treatment

    Indian Academy of Sciences (India)

    Manoj Komath; P Rajesh; C V Muraleedharan; H K Varma; R Reshmi; M K Jayaraj

    2011-04-01

    Pulsed laser deposition (PLD) has emerged as an acceptable technique to coat hydroxyapatite on titanium-based permanent implants for the use in orthopedics and dentistry. It requires substrate temperature higher than 400°C to form coatings of good adhesion and crystallinity. As this range of temperatures is likely to affect the bulk mechanical properties of the implant, lowering the substrate temperature during the coating process is crucial for the long-term performance of the implant. In the present study, hydroxyapatite target was ablated using a pulsed Nd:YAG laser (355 nm) onto commercially pure titanium substrates kept at 200°C. The coating thus obtained has been subjected to hydrothermal treatment at 200°C in an alkaline medium. The coatings were analysed using microscratch test, optical profilometry, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and infrared spectroscopy (FTIR). XRD, EDS and FTIR showed that the as-deposited coating contained amorphous calcium phosphate and the hydrothermal treatment converted it into crystalline hydroxyapatite. The micro-morphology was granular, with an average size of 1 micron. In the microscratch test, a remarkable increase in adhesion with the substrate was seen as a result of the treatment. The plasma plume during the deposition has been analysed using optical emission spectroscopy, which revealed atomic and ionic species of calcium, phosphorous and oxygen. The outcomes demonstrate the possibility of obtaining adherent and crystalline hydroxyapatite on titanium substrate at 200°C through pulsed laser deposition and subsequent hydrothermal treatment.

  12. Optical and Micro-Structural Properties of ZnO Thin Films Grown on Silicon Substrate by Pulsed Laser Deposition

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    ZnO thin films were deposited on n-Si (111) at various substrate temperatures and oxygen pressures by pulsed laser deposition (PLD) using a Nd∶YAG laser with the wavelength of 1064 nm. X-ray diffraction (XRD), photoluminescence (PL), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the microstructure, optical property and morphology of the ZnO thin films. A comparatively optimal crystallized ZnO thin film was obtained at the substrate temperature of 600 ℃ in oxygen pressure of 50 mTorr. The intensity of the luminescence strongly depends on the stoichiometry of the film as well as the crystalline quality.

  13. Diamond-like carbon formation for various positions by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yap, Seong-Shan [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)]. E-mail: ssyap@mmu.edu.my; Tou, Teck-Yong [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia)

    2005-07-30

    Pulsed laser ablation of pyrolytic graphite target was carried out by an Nd-YAG laser with {lambda} = 1064 nm and fluence in the range of 1-10 J/cm{sup 2}. The plume was produced by focusing the laser beam and rastering over a 6.5 mm x 6.5 mm area on the graphite target. The substrates were placed at two positions: on-axis position facing the target and off-axis position in the target plane with 2 mm offset from the ablation site. Diamond-like carbon was formed on the substrates at both positions and on the ablated area as detected by Raman spectroscopy. Rough and granular surface was observed for the samples placed in the target plane and smooth diamond-like carbon films for the samples placed facing the target as observed by SEM and optical microscopy.

  14. Physical characterization of Ge films on polyethylene obtained by pulsed laser deposition

    Science.gov (United States)

    Giuffrida, L.; Torrisi, L.; Rosinski, M.; Caridi, F.; Cutroneo, M.

    2012-05-01

    A Nd:YAg laser, operating in fundamental wavelength at 1064 nm, is focused at an intensity of the order of 1010 W/cm2 to ablate a solid Ge target. A Laser Ion Source (LIS) system is employed to produce ion emission at high directionality, high current, high rate of production and high charge states. LIS is used to implant and/or to deposit Ge ions in polyethylene (UHMWPE). Mechanical (roughness, wetting ability and microhardness), optical (reflectivity and transmission) and electrical properties (resistivity) were investigated, in comparison to the pristine values, in order to reach understanding of the ion implantation/deposition effects as a function of the irradiation ion dose.

  15. Physical characterization of Ge films on polyethylene obtained by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Giuffrida, L. [INFN-Laboratori Nazionali del Sud, Catania (Italy); Torrisi, L. [INFN-Laboratori Nazionali del Sud, Catania (Italy); Universita di Messina, Dipartimento di Fisica, Messina (Italy); Rosinski, M. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Caridi, F. [Universita di Messina, Facolta di Scienze MM.FF.NN., Messina (Italy); INFN-Sez. CT, Gr. Coll. di ME, Messina (Italy); Cutroneo, M. [Universita di Messina, Dipartimento di Fisica, Messina (Italy); INFN-Sez. CT, Gr. Coll. di ME, Messina (Italy)

    2012-05-15

    A Nd:YAg laser, operating in fundamental wavelength at 1064 nm, is focused at an intensity of the order of 10{sup 10} W/cm{sup 2} to ablate a solid Ge target. A Laser Ion Source (LIS) system is employed to produce ion emission at high directionality, high current, high rate of production and high charge states. LIS is used to implant and/or to deposit Ge ions in polyethylene (UHMWPE). Mechanical (roughness, wetting ability and microhardness), optical (reflectivity and transmission) and electrical properties (resistivity) were investigated, in comparison to the pristine values, in order to reach understanding of the ion implantation/deposition effects as a function of the irradiation ion dose. (orig.)

  16. Correlations between optical properties, microstructure, and processing conditions of Aluminum nitride thin films fabricated by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Jonghoon [Department of Electrical and Computer Engineering, Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States)]. E-mail: jhoon6@hotmail.com; Ma, James [Materials Science and Engineering Program, Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States); Becker, Michael F. [Department of Electrical and Computer Engineering, Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States); Keto, John W. [Department of Physics, Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States); Kovar, Desiderio [Department of Mechanical Engineering, Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States)

    2007-06-25

    Aluminum nitride (AlN) films were deposited using pulsed laser deposition (PLD) onto sapphire (0001) substrates with varying processing conditions (temperature, pressure, and laser fluence). We have studied the dependence of optical properties, structural properties and their correlations for these AlN films. The optical transmission spectra of the produced films were measured, and a numerical procedure was applied to accurately determine the optical constants for films of non-uniform thickness. The microstructure and texture of the films were studied using various X-ray diffraction techniques. The real part of the refractive index was found to not vary significantly with processing parameters, but absorption was found to be strongly dependent on the deposition temperature and the nitrogen pressure in the deposition chamber. We report that low optical absorption, textured polycrystalline AlN films can be produced by PLD on sapphire substrates at both low and high laser fluence using a background nitrogen pressure of 6.0 x 10{sup -2} Pa (4.5 x 10{sup -4} Torr) of 99.9% purity.

  17. The influence of substrate temperature and deposition pressure on pulsed laser deposited thin films of CaS:Eu{sup 2+} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Nyenge, R.L. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9300 (South Africa); Physics Department, Kenyatta University, P.O. Box 43844-0100, Nairobi (Kenya); Swart, H.C. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9300 (South Africa); Ntwaeaborwa, O.M., E-mail: ntwaeab@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9300 (South Africa)

    2016-01-01

    The aim of this study was to investigate the influence of substrate temperature and argon deposition pressure on the structure, morphology and photoluminescence emission (PL) properties of pulsed laser deposited thin films of CaS:Eu{sup 2+}. The PL intensity improved significantly upon reaching substrate temperature of 650 °C. The (200) peak gradually became the preferred orientation. The increase in PL intensity as well as surface roughness is attributed to improved crystallinity and higher growth rates, respectively. The best PL intensity as a function of deposition pressure was obtained at an argon pressure of 80 mTorr. The initial increase and eventual drop in PL intensity as deposition pressure increases is ascribed to the changes in growth rates.

  18. Effect of deuterium ion beam irradiation onto the mirror-like pulsed laser deposited thin films of rhodium

    Energy Technology Data Exchange (ETDEWEB)

    Mostako, A.T.T., E-mail: abu@iitg.ernet.in [Laser and Photonics Lab, Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India); Khare, Alika [Laser and Photonics Lab, Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India); Rao, C.V.S.; Vala, Sudhirsinh; Makwana, R.J.; Basu, T.K. [Neutronics Lab, Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2015-01-01

    Highlights: • Rh mirror like thin films are fabricated by PLD technique for FM application. • Rh thin film FMs are irradiated with 10, 20, and 30 keV D ion beam. • Effect of D ion beam irradiation on Rh FM’s reflectivity is investigated. - Abstract: The effect of deuterium ion beam irradiation on the reflectivity of mirror-like pulsed laser deposited (PLD) thin film of rhodium is reported. The deposition parameters; target-substrate distance and background helium gas pressure were optimized to obtain the good quality rhodium films, of higher thickness, oriented preferentially in (1 1 1) plane. The rhodium thin films deposited at optimum PLD parameters were exposed to 10, 20, and 30 keV deuterium ion beam. The changes in surface morphology and UV–Visible–FIR reflectivity of mirror-like rhodium thin films, as a function of energy of deuterium ion beam, after exposure are reported.

  19. Tailoring out-of-plane magnetic properties of pulsed laser deposited FePt thin films by changing laser energy fluence

    Science.gov (United States)

    Wang, Ying; Tan, T. L.; Tan, K. S.; Lee, P.; Liu, Hai; Yadian, Boluo; Hu, Ge; Huang, Yizhong; Ramanujan, R. V.; Rawat, R. S.

    2014-10-01

    Magnetic properties of pulsed laser deposited (PLD) FePt thin films are investigated at three different laser energy fluences of 51, 136 and 182 J/cm2. Deposition at lower laser energy fluence (51 J/cm2) yields softer out-of-plane coercivity (≤0.4 kG), whereas deposition at higher laser energy fluence (136 and 182 J/cm2) results in harder out-of-plane coercivity (≥5.0 kG). The improved coercivity is found to be attributed to the formation of vacancy defects in thin films, which is indicated by stress change from tensile to compressive form with increasing laser energy fluence. Maximum out-of-plane saturated magnetization of 615 emu/cm3 and remanent squareness ratio of 0.88 are achieved for 16 nm thick FePt thin films deposited at moderate laser energy fluence of 136 J/cm2, making them suitable for high density perpendicular data storage applications.

  20. Growth of poly-crystalline Cu films on Y substrates by picosecond pulsed laser deposition for photocathode applications

    Science.gov (United States)

    Gontad, F.; Lorusso, A.; Klini, A.; Manousaki, A.; Perrone, A.; Fotakis, C.

    2015-11-01

    In this work, the deposition of Cu thin films on Y substrates for photocathode applications by pulsed laser deposition employing picosecond laser pulses is reported and compared with the use of nanosecond pulses. The influence of power density (6-50 GW/cm2) on the ablation of the target material, as well as on the properties of the resulting film, is discussed. The material transfer from the target to the substrate surface was found to be rather efficient, in comparison to nanosecond ablation, leading to the growth of films with high thickness. Scanning electron microscope analysis indicated a quasi-continuous film morphology, at low power density values, becoming granular with increasing power density. The structural investigation, through X-ray diffraction, revealed the poly-crystalline nature of the films, with a preferential growth along the (111) crystallographic orientation of Cu cubic network. Finally, energy-dispersive X-ray spectroscopy showed a low contamination level of the grown films, demonstrating the potential of a PLD technique for the fabrication of Cu/Y patterned structures, with applications in radiofrequency electron gun technology.

  1. Cr13Ni5Si2-Based Composite Coating on Copper Deposited Using Pulse Laser Induction Cladding

    Directory of Open Access Journals (Sweden)

    Ke Wang

    2017-02-01

    Full Text Available A Cr13Ni5Si2-based composite coating was successfully deposited on copper by pulse laser induction hybrid cladding (PLIC, and its high-temperature wear behavior was investigated. Temperature evolutions associated with crack behaviors in PLIC were analyzed and compared with pulse laser cladding (PLC using the finite element method. The microstructure and present phases were analyzed using scanning electron microscopy and X-ray diffraction. Compared with continuous laser induction cladding, the higher peak power offered by PLIC ensures metallurgical bonding between highly reflective copper substrate and coating. Compared with a wear test at room temperature, at 500 °C the wear volume of the Cr13Ni5Si2-based composite coating increased by 21%, and increased by 225% for a NiCr/Cr3C2 coating deposited by plasma spray. This novel technology has good prospects for application with respect to the extended service life of copper mold plates for slab continuous casting.

  2. Cr13Ni5Si2-Based Composite Coating on Copper Deposited Using Pulse Laser Induction Cladding

    Science.gov (United States)

    Wang, Ke; Wang, Hailin; Zhu, Guangzhi; Zhu, Xiao

    2017-01-01

    A Cr13Ni5Si2-based composite coating was successfully deposited on copper by pulse laser induction hybrid cladding (PLIC), and its high-temperature wear behavior was investigated. Temperature evolutions associated with crack behaviors in PLIC were analyzed and compared with pulse laser cladding (PLC) using the finite element method. The microstructure and present phases were analyzed using scanning electron microscopy and X-ray diffraction. Compared with continuous laser induction cladding, the higher peak power offered by PLIC ensures metallurgical bonding between highly reflective copper substrate and coating. Compared with a wear test at room temperature, at 500 °C the wear volume of the Cr13Ni5Si2-based composite coating increased by 21%, and increased by 225% for a NiCr/Cr3C2 coating deposited by plasma spray. This novel technology has good prospects for application with respect to the extended service life of copper mold plates for slab continuous casting. PMID:28772519

  3. Calcium phosphate thin films synthesized by pulsed laser deposition: Physico-chemical characterization and in vitro cell response

    Energy Technology Data Exchange (ETDEWEB)

    Mihailescu, I.N. [National Institute for Lasers, Plasma and Radiation Physics, 77125 Bucharest-Magurele (Romania)]. E-mail: mihailes@ifin.nipne.ro; Torricelli, P. [Servizio di Chirurgia Sperimentale-Istituto di Ricerca Codivilla PuttiIOR, Bologna (Italy); Bigi, A. [Department of Chemistry ' G. Ciamician' , University of Bologna, 40126 Bologna (Italy); Mayer, I. [Department of Inorganic and Analytical Chemistry, Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Iliescu, M. [Institute of Physics and Chemistry of Materials, 67037 Strasbourg (France); Werckmann, J. [Institute of Physics and Chemistry of Materials, 67037 Strasbourg (France); Socol, G. [National Institute for Lasers, Plasma and Radiation Physics, 77125 Bucharest-Magurele (Romania); Miroiu, F. [National Institute for Lasers, Plasma and Radiation Physics, 77125 Bucharest-Magurele (Romania); Cuisinier, F. [Institut National de la Sante et de la Recherche Medicale, 67085 Strasbourg (France); Elkaim, R. [Institut National de la Sante et de la Recherche Medicale, 67085 Strasbourg (France); Hildebrand, G. [IBA e.V., Department of Biomaterials, Rosenhof, D-37308 Heilbad Heiligenstadt (Germany)

    2005-07-30

    We review the progress made by us using pulsed laser deposition (PLD) of two bioactive calcium phosphates: octacalcium phosphate (OCP) and Mn doped carbonated hydroxyapatite (Mn-CHA). Coatings of these materials well suited for biomimetic medical prostheses and pivots were synthesized on titanium substrates with a pulsed KrF* UV laser source. The best deposition conditions for Mn-CHA thin films were 13 Pa O{sub 2}, 400 deg. C with post heat treatment of 6 h in air enriched with water vapours. The coatings are stoichiometric and crystalline. For OCP, deposition at 150 deg. C in 50 Pa water vapor atmosphere, post treated by 6 h annealing in hot flux of water vapours, resulted in stoichiometric, but poorly-crystallized films. Degradation tests show different behavior for the OCP and Mn-CHA coatings. In vitro cell growth shows excellent adherence and biocompatibility of osteoblasts and fibroblasts in both OCP and Mn-CHA coatings. Human osteoblasts display normal proliferation and viability, and good differentiation behaviour.

  4. Deposition of matrix-free fullerene films with improved morphology by matrix-assisted pulsed laser evaporation (MAPLE)

    DEFF Research Database (Denmark)

    Canulescu, Stela; Schou, Jørgen; Fæster, Søren;

    2013-01-01

    Thin films of C60 were deposited by matrix-assisted pulsed laser evaporation (MAPLE) from a frozen target of anisole with 0.67 wt% C60. Above a fluence of 1.5 J/cm2 the C60 films are strongly non-uniform and are resulting from transfer of matrix-droplets containing fullerenes. At low fluence...... the fullerene molecules in the films are intact, the surface morphology is substantially improved and there are no measurable traces of the matrix molecules in the film. This may indicate a regime of dominant evaporation at low fluence which merges into the MAPLE regime of liquid ejection of the host matrix...

  5. In situ growth of p and n-type graphene thin films and diodes by pulsed laser deposition

    KAUST Repository

    Sarath Kumar, S. R.

    2013-11-07

    We report the in situ growth of p and n-type graphene thin films by ultraviolet pulsed laser deposition in the presence of argon and nitrogen, respectively. Electron microscopy and Raman studies confirmed the growth, while temperature dependent electrical conductivity and Seebeck coefficient studies confirmed the polarity type of graphene films. Nitrogen doping at different sites of the honeycomb structure, responsible for n-type conduction, is identified using X-ray photoelectron spectroscopy, for films grown in nitrogen. A diode-like rectifying behavior is exhibited by p-n junction diodes fabricated using the graphene films.

  6. Ion beam induced chemical and morphological changes in TiO{sub 2} films deposited on Si(1 1 1) surface by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mohanta, R.R. [Department of Chemistry, Krupajal Engineering College, Bhubaneswar 751002 (India); Medicherla, V.R.R., E-mail: mvramarao1@gmail.com [Department of Physics, Institute of Technical Education and Research, Siksha ‘O’ Anusandhan University, Bhubaneswar 751030 (India); Mohanta, K.L. [Department of Physics, Institute of Technical Education and Research, Siksha ‘O’ Anusandhan University, Bhubaneswar 751030 (India); Nayak, Nimai C. [Department of Chemistry, Institute of Technical Education and Research, Siksha ‘O’ Anusandhan University, Bhubaneswar 751030 (India); Majumder, S.; Solanki, V.; Varma, Shikha [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Bapna, Komal; Phase, D.M.; Sathe, V. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017 (India)

    2015-01-15

    Highlights: • Pulsed laser deposition of TiO{sub 2} films on Si(1 1 1) surface. • XPS and AFM study of TiO{sub 2} surface. • Ion beam treatment induced morphology. • Chemical reduction of TiO{sub 2} on the surface. • A-ray induced Auger transition of Ti LMM. - Abstract: We have investigated TiO{sub 2} films prepared by pulsed laser deposition method on Si(1 1 1) surface using X-ray diffraction (XRD), Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM) and ion beam sputtering techniques. Our XRD data along with Raman indicated that the deposited TiO{sub 2} is in anatase phase. The binding energy position of Ti 2p also supports the anatase phase formation. AFM topography of as deposited film indicates the formation of non uniform TiO{sub 2} growth with the formation of voids on Si(1 1 1) substrate. After sputtering with argon ion beam, surface erosion occurs and voids have disappeared. The Ti 2p core level of sputtered TiO{sub 2} exhibits the formation of Ti{sub 2}O{sub 3}, TiO and pure Ti on the surface. High binding energy shoulder of O 1s peak becomes sharp after sputtering. Ti LMM Auger peaks become broader after sputtering but no shift in kinetic energy is observed.

  7. Laminated CeO2/HfO2 High-K Gate Dielectrics Grown by Pulsed Laser Deposition in Reducing Ambient

    NARCIS (Netherlands)

    Karakaya, K.; Barcones, B.; Zinine, A.; Rittersma, Z.M.; Graat, P.; Berkum, van J.G.M.; Verheijen, M.A.; Rijnders, G.; Blank, D.H.A.

    2006-01-01

    CeO2 and HfO2 dielectric layers were deposited in an Ar+(5%)H2 gas mixture by Pulsed Laser Deposition (PLD) on Si (100). A CeO2-Ce2O3 transformation is achieved by deposition in reducing ambient. It is also shown that in-situ post deposition anneal efficiently oxidizes Ce2O3 layers to CeO2. The prop

  8. The effects of thermal annealing on the structure and the electrical transport properties of ultrathin gadolinia-doped ceria films grown by pulsed laser deposition

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Heiroth, S.; Pryds, Nini;

    2011-01-01

    Ultrathin crystalline films of 10 mol% gadolinia-doped ceria (CGO10) are grown on MgO (100) substrates by pulsed laser deposition at a moderate temperature of 400°C. As-deposited CGO10 layers of approximately 4 nm, 14 nm, and 22 nm thickness consist of fine grains with dimensions ≤∼11 nm. The films...

  9. Imposed quasi-layer-by-layer homoepitaxial growth of SrTiO3 films by large area pulsed laser deposition

    DEFF Research Database (Denmark)

    Chen, Yunzhong; Pryds, Nini

    2011-01-01

    The homoepitaxial growth of SrTiO3 (STO) films was investigated by a large-area pulsed laser deposition (PLD), which was in-situ monitored by a high pressure reflective high energy electron diffraction. By combining a conventionally continuous film deposition with a followed interval relaxation, ...

  10. Tailoring of LaxSr1‐xCoyFe1‐yO3‐δ Nanostructure by Pulsed Laser Deposition

    DEFF Research Database (Denmark)

    Plonczak, Pawel; Bieberle‐Hütter, Anja; Søgaard, Martin

    2011-01-01

    Pulsed Laser Deposition (PLD) was used to prepare thin films with the nominal composition La0.58Sr0.4Co0.2Fe0.8O3‐δ (LSCF). The thin film microstructure was investigated as a function of PLD deposition parameters such as: substrate temperature, ambient gas pressure, target‐to‐substrate distance, ...

  11. Influence of the oxidation state of SrTiO3 plasmas for stoichiometric growth of pulsed laser deposition films identified by laser induced fluorescence

    Directory of Open Access Journals (Sweden)

    Kasper Orsel

    2015-10-01

    Full Text Available By applying two-dimensional laser induced fluorescence (LIF on multiple plasma constituents, we are able to directly link the oxidation of plasma species in a SrTiO3 plasma for pulsed laser deposition to the stoichiometry and quality of the thin films grown. With spatiotemporal LIF mapping of the plasma species in different background gas compositions, we find that Ti and Sr have to be fully oxidized for a stoichiometric growth of crystalline thin films, which gives new input for modeling surface growth, as well as provides additional control over the exact degree of stoichiometry of thin films.

  12. Time-Resolved Observation of Deposition Process of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films in Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Kenji Hanada

    2009-01-01

    Full Text Available Optical emission spectroscopy was used to study pulsed laser ablation of graphite in a hydrogen atmosphere wherein ultrananocrystalline diamond (UNCD/hydrogenated amorphous carbon (a-C:H composite films were grown on heated substrates. Time-resolved photographs of a plume that expanded from a laser-irradiation spot toward a substrate were taken using a high-speed ICCD camera equipped with narrow-bandpass filters. While the emissions from C atoms and C2 dimers lasted above the laser-irradiation spot on the target, the emission from C+ ions lasted above the substrate surface for approximately 7 microseconds, although the emission lifetime of species is generally approximately 10 nanoseconds. This implies that C+ ions actively collided with each other above the substrate surface for such a long time. We believe that the keys to UNCD growth in PLD are the supply of highly energetic carbon species at a high density to the substrate and existence of atomic hydrogen during the growth.

  13. Ge nanocrystals with highly uniform size distribution deposited on alumina at room temperature by pulsed laser deposition: structural, morphological, and charge trapping properties

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Sanchez, J., E-mail: javier.martin.nano@gmail.com; Marques, L.; Vieira, E. M. F. [University of Minho, Department of Physics and Centre of Physics (Portugal); Doan, Q. T.; Marchand, A.; El Hdiy, A. [LMEN, Universite de Reims Champagne-Ardenne (France); Rolo, A. G.; Pinto, S. R. C.; Ramos, M. M. D.; Chahboun, A.; Gomes, M. J. M. [University of Minho, Department of Physics and Centre of Physics (Portugal)

    2012-05-15

    In this work, we report on the synthesis of Ge nanocrystals (NCs) by pulsed laser deposition (PLD) at room temperature (RT) in an argon atmosphere without any further annealing process. Our results show that functional thin films of crystalline Ge nanoparticles with spherical shapes can be obtained by PLD directly on alumina layers deposited on n-doped Si (100) substrates. In addition, we also demonstrate that a uniform size distribution of NCs with an average diameter of about 3 nm and a density of 2.3 Multiplication-Sign 10{sup 11} cm{sup -2} can be obtained by optimizing a shadow mask set-up, where a solid disk is introduced between the target and the substrate. Charge/discharge effects in Ge NCs deposited on a high-k amorphous alumina layer are also evidenced by conductive atomic force microscopy, which makes them suitable for memory applications.

  14. Growth of centimeter-scale atomically thin MoS{sub 2} films by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Siegel, Gene; Venkata Subbaiah, Y. P.; Prestgard, Megan C.; Tiwari, Ashutosh, E-mail: tiwari@eng.utah.edu [Nanostructured Materials Research Laboratory, Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)

    2015-05-01

    We are reporting the growth of single layer and few-layer MoS{sub 2} films on single crystal sapphire substrates using a pulsed-laser deposition technique. A pulsed KrF excimer laser (wavelength: 248 nm; pulse width: 25 ns) was used to ablate a polycrystalline MoS{sub 2} target. The material thus ablated was deposited on a single crystal sapphire (0001) substrate kept at 700 °C in an ambient vacuum of 10{sup −6} Torr. Detailed characterization of the films was performed using atomic force microscopy (AFM), Raman spectroscopy, UV-Vis spectroscopy, and photoluminescence (PL) measurements. The ablation of the MoS{sub 2} target by 50 laser pulses (energy density: 1.5 J/cm{sup 2}) was found to result in the formation of a monolayer of MoS{sub 2} as shown by AFM results. In the Raman spectrum, A{sub 1g} and E{sup 1}{sub 2g} peaks were observed at 404.6 cm{sup −1} and 384.5 cm{sup −1} with a spacing of 20.1 cm{sup −1}, confirming the monolayer thickness of the film. The UV-Vis absorption spectrum exhibited two exciton absorption bands at 672 nm (1.85 eV) and 615 nm (2.02 eV), with an energy split of 0.17 eV, which is in excellent agreement with the theoretically predicted value of 0.15 eV. The monolayer MoS{sub 2} exhibited a PL peak at 1.85 eV confirming the direct nature of the band-gap. By varying the number of laser pulses, bi-layer, tri-layer, and few-layer MoS{sub 2} films were prepared. It was found that as the number of monolayers (n) in the MoS{sub 2} films increases, the spacing between the A{sub 1g} and E{sup 1}{sub 2g} Raman peaks (Δf) increases following an empirical relation, Δf=26.45−(15.42)/(1+1.44 n{sup 0.9}) cm{sup −1}.

  15. Large third-order optical nonlinearities in iron oxide thin films synthesized by reactive pulsed laser deposition

    Science.gov (United States)

    Mulenko, S. A.; Rudenko, V. I.; Liakhovetskyi, V. R.; Brodin, A. M.; Stefan, N.

    2016-10-01

    We report on a study of the third-order nonlinear optical properties of Fe2O3 thin films, grown by the method of laser deposition on silica (SiO2) substrates. The films were synthesized on substrates at different temperatures (293 K and 800 K) and under different oxygen pressures (0.1 Pa, 0.5 Pa, 1.0 Pa). The resulting films were amorphous, if grown on cold substrates (293 K), or polycrystalline otherwise. The third-order optical susceptibility χ(3) of the films was determined by the Z-scan method at the wavelengths of 1064 nm and 532 nm and the laser pulse width of 20 ns. Remarkably high χ(3) values on the order of 10-4 esu at 1064 nm are obtained. The results show that Fe2O3 thin films are promising nonlinear materials for contemporary optoelectronics.

  16. Upconversion emission in Er{sup 3+}-doped lead niobium germanate thin-film glasses produced by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lahoz, F.; Haro-Gonzalez, P.; Rivera-Lopez, F.; Gonzalez-Perez, S.; Martin, I.R. [University of La Laguna, Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, La Laguna, Tenerife (Spain); Capuj, N.E. [University of La Laguna, Departamento de Fisica Basica, La Laguna, Tenerife (Spain); Afonso, C.N.; Gonzalo, J. [CSIC, Laser Processing Group, Instituto de Optica, Madrid (Spain); Fernandez, J.; Balda, R. [Escuela Superior de Ingenieros, Departamento de Fisica Aplicada I, Bilbao (Spain); Centro Mixto CSIC-UPV/EHU and DIPC, Donostia (Spain)

    2008-11-15

    Thin films of Er{sup 3+}-doped lead-niobium germanate have been produced by pulsed laser deposition from Er{sup 3+}-doped 25PbO{sub 2}-25Nb{sub 2}O{sub 5}-50GeO{sub 2} (mol%) transparent glasses with an Er content in the range 0.5-3 wt%. The room-temperature infrared to visible upconversion properties of these thin films have been investigated under 800-nm laser excitation. An energy transfer upconversion mechanism has been identified to be responsible for the population of the {sup 4}S{sub 3/2}:{sup 2}H{sub 11/2} excited level, from which an intense green emission occurs. A rate equation analysis supports the proposed mechanism. (orig.)

  17. Debris reduction for copper and diamond-like carbon thin films produced by magnetically guided pulsed laser deposition

    CERN Document Server

    Tsui, Y Y; Vick, D; Fedosejevs, R

    2002-01-01

    The effectiveness of debris reduction using magnetically guided pulsed laser deposition (MGPLD) is reported here. KrF laser pulses (248 nm) of 100 mJ energy were focused to intensities of 6x10 sup 9 W/cm sup 2 onto the surface of a copper or a carbon source target and a magnetic field of 0.3 T as used to steer the plasma around a curved arc of 0.5 m length to the deposition substrate. Debris counts were compared for films produced by the MGPLD and conventional PLD (nonguided) techniques. A significant reduction in particulates of size greater than 0.1 mu m was achieved using MGPLD. For the copper films, particulate count was reduced from 150 000 particles/cm sup 2 /nm to 50 particulates/cm sup 2 /nm and for diamond-like carbon thin films particulate count was reduced from 25 000 particles/cm sup 2 /nm to 1200 particles/cm sup 2 /nm.

  18. Electrical and photoelectric properties of transparent Li-doped ZnO/ZnO homojunctions by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shihui; Ding, Linghong; Zheng, Haiwu; Xue, Chuang; Chen, Li; Zhang, Weifeng, E-mail: wfzhang@henu.edu.cn

    2013-07-01

    (002)-Preferred orientation ZnO and Li-doped ZnO thin films on glass substrates and Li-doped ZnO/ZnO bilayers on fluorine-doped SnO{sub 2} glass substrates are grown by pulsed laser deposition technique. These films are characterized by X-ray diffraction, UV–visible transmission spectroscopy, surface photovoltage spectroscopy, and electric measurements. The optical transmittance of Li-doped ZnO/ZnO bilayers is about 86%. The bilayer grown on FTO glass substrates exhibits a typical rectifying characteristic of p–n heterojunctions. In addition, the photovoltaic response of ZnO is blue-shifted from 380 to 363 nm and greatly enhanced resulting from the formation of p–n homojunctions based on ZnO. - Highlights: • Li-doped ZnO/ZnO p–n bilayers are grown on F-doped SnO{sub 2} by pulsed laser deposition. • The bilayers exhibit a typical rectifying characteristic of p–n heterojunctions. • Formation of homojunctions greatly enhanced the ZnO photovoltaic response.

  19. Epitaxial LaFeAsO{sub 1-x}F{sub x} thin films grown by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kidszun, M; Haindl, S; Reich, E; Haenisch, J; Iida, K; Schultz, L; Holzapfel, B, E-mail: M.Kidszun@ifw-dresden.d [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany)

    2010-02-15

    Superconducting and epitaxially grown LaFeAsO{sub 1-x}F{sub x} thin films were successfully prepared on (001)-oriented LaAlO{sub 3} substrates using pulsed laser deposition. The prepared thin films show exclusively a single in-plane orientation with the epitaxial relation (001)[100]||(001)[100] and a full width at half-maximum value of 1{sup 0}. Furthermore, resistive measurement of the superconducting transition temperature revealed a T{sub c,90%} of 25 K with a high residual resistive ratio of 6.8. The preparation technique applied, standard thin film pulsed laser deposition at room temperature in combination with a subsequent post-annealing process, is suitable for fabrication of high quality LaFeAsO{sub 1-x}F{sub x} thin films. A high upper critical field of 76.2 T was evaluated for magnetic fields applied perpendicular to the c-axis and the anisotropy was calculated to be 3.3 assuming single band superconductivity. (rapid communication)

  20. Production of biologically inert Teflon thin layers on the surface of allergenic metal objects by pulsed laser deposition technology

    Science.gov (United States)

    Hopp, B.; Smausz, T.; Kresz, N.; Nagy, P. M.; Juhász, A.; Ignácz, F.; Márton, Z.

    Allergic-type diseases are current nowadays, and they are frequently caused by certain metals. We demonstrated that the metal objects can be covered by Teflon protective thin layers using a pulsed laser deposition procedure. An ArF excimer laser beam was focused onto the surface of pressed PTFE powder pellets; the applied fluences were 7.5-7.7 J/cm2. Teflon films were deposited on fourteen-carat gold, silver and titanium plates. The number of ablating pulses was 10000. Post-annealing of the films was carried out in atmospheric air at oven temperatures between 320 and 500 °C. The thickness of the thin layers was around 5 μm. The prepared films were granular without heat treatment or after annealing at a temperature below 340 °C. At 360 °C a crystalline, contiguous, smooth, very compact and pinhole-free thin layer was produced; a melted and re-solidified morphology was observed above 420 °C. The adhesion strength between the Teflon films and the metal substrates was determined. This could exceed 1-4 MPa depending on the treatment temperature. It was proved that the prepared Teflon layers can be suitable for prevention of contact between the human body and allergen metals and so for avoidance of metal allergy.

  1. Growth and characterization of polycrystalline Ge{sub 1-x}C{sub x} by reactive pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, M.P., E-mail: mayrap@fisica.uh.cu [Instituto de Ciencia y Tecnologia de Materiales, Zapata y G, P.O. Box 10400, Universidad de La Habana (Cuba); Farias, M.H.; Castillon, F.F.; Diaz, Jesus A.; Avalos, M. [Centro de Nanociencias y Nanotecnologia, Universidad Nacional Autonoma de Mexico, Km 107 Carretera Tijuana-Ensenada, C.P. 22800 Ensenada, Baja California (Mexico); Ulloa, L. [Universidad de Guadalajara, (CUCEI) Blvd. Marcelino Garcia Barragan 1421, C.P. 44430 Guadalajara, Jalisco (Mexico); Gallegos, J.A.; Yee-Madeiros, H. [Escuela Superior de Fisica y Matematicas-IPN, UP' ALM' , Colonia Lindavista 07738 (Mexico)

    2011-03-15

    Polycrystalline thin films of Ge-C were grown on Si (1 1 1) substrates by means of reactive pulsed laser deposition with methane pressure of 100 mTorr. Effect substrate temperature, T{sub s}, on C incorporation to substitutional sites (x) in Ge{sub 1-x}C{sub x} was investigated systematically by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyzes. The substrate temperatures were ranging from 250 to 400 deg. C. The substitutional C composition x in the films by XRD were estimated using the Vegard's linear law. The maximum value of x calculated by XRD was 0.032 for T{sub s} of 350 deg. C. The position of the C 1s peak at 283.4 eV in the XPS spectrum confirmed the germanium-carbon alloys. XRD measurements indicated that x increased with T{sub s} from 250 deg. C to 350 deg. C. At T{sub s} = 400 deg. C, the estimation of x was lowered. However, the C content calculated by XPS analyzes increased with T{sub s} being more these values than substitutional C composition x. XPS and XRD analyzes demonstrate that the remaining C atoms are incorporated to interstitial sites. The use of the T{sub s} plays important roles in the incorporation of substitutional C and in restraining C-cluster formation in the reactive pulsed laser deposition growth of Ge-C/Si.

  2. Low temperature synthesis of hierarchical TiO2 nanostructures for high performance perovskite solar cells by pulsed laser deposition.

    Science.gov (United States)

    Yang, Bin; Mahjouri-Samani, Masoud; Rouleau, Christopher M; Geohegan, David B; Xiao, Kai

    2016-10-21

    A promising way to advance perovskite solar cells is to improve the quality of the electron transport material -e.g., titanium dioxide (TiO2) - in a direction that increases electron transport and extraction. Although dense TiO2 films are easily grown in solution, efficient electron extraction suffers due to a lack of interfacial contact area with the perovskites. Conversely, mesoporous films do offer high surface-area-to-volume ratios, thereby promoting efficient electron extraction, but their morphology is relatively difficult to control via conventional solution synthesis methods. Here, a pulsed laser deposition method was used to assemble TiO2 nanoparticles into TiO2 hierarchical architectures exhibiting an anatase crystal structure, and prototype solar cells employing these structures yielded power conversion efficiencies of ∼14%. Our approach demonstrates a way to grow high aspect-ratio TiO2 nanostructures for improved interfacial contact between TiO2 and perovskite materials, leading to high electron-hole pair separation and electron extraction efficiencies for superior photovoltaic performance. Compared to previous pulsed laser deposition-synthesized TiO2 mesoporous crystalline networks that needed post-thermal annealing at 500 °C to form mesoporous crystalline networks, our relatively low temperature (300 °C) TiO2 processing method may promote reduced energy-consumption during device fabrication, as well as enable compatibility with flexible polymer substrates such as polyimide.

  3. Nanomechanical and electrical properties of Nb thin films deposited on Pb substrates by pulsed laser deposition as a new concept photocathode for superconductor cavities

    Energy Technology Data Exchange (ETDEWEB)

    Gontad, F. [University of Salento, Department of Mathematics and Physics “E. De Giorgi”, 73100 Lecce (Italy); National Institute of Nuclear Physics, 73100 Lecce (Italy); Lorusso, A., E-mail: antonella.lorusso@le.infn.it [University of Salento, Department of Mathematics and Physics “E. De Giorgi”, 73100 Lecce (Italy); National Institute of Nuclear Physics, 73100 Lecce (Italy); Panareo, M.; Monteduro, A.G.; Maruccio, G. [University of Salento, Department of Mathematics and Physics “E. De Giorgi”, 73100 Lecce (Italy); National Institute of Nuclear Physics, 73100 Lecce (Italy); Broitman, E. [Thin Film Physics Division, IFM, Linköping University, 581-83 Linköping (Sweden); Perrone, A. [University of Salento, Department of Mathematics and Physics “E. De Giorgi”, 73100 Lecce (Italy); National Institute of Nuclear Physics, 73100 Lecce (Italy)

    2015-12-21

    We report a design of photocathode, which combines the good photoemissive properties of lead (Pb) and the advantages of superconducting performance of niobium (Nb) when installed into a superconducting radio-frequency gun. The new configuration is obtained by a coating of Nb thin film grown on a disk of Pb via pulsed laser deposition. The central emitting area of Pb is masked by a shield to avoid the Nb deposition. The nanomechanical properties of the Nb film, obtained through nanoindentation measurements, reveal a hardness of 2.8±0.3 GPa, while the study of the electrical resistivity of the film shows the appearance of the superconducting transitions at 9.3 K and 7.3 K for Nb and Pb, respectively, very close to the bulk material values. Additionally, morphological, structural and contamination studies of Nb thin film expose a very low droplet density on the substrate surface, a small polycrystalline orientation of the films and a low contamination level. These results, together with the acceptable Pb quantum efficiency of 2×10{sup −5} found at 266 nm, demonstrate the potentiality of the new concept photocathode. - Highlights: • Fabrication of hybrid Nb/Pb photocathodes for superconductive photoinjectors. • Nb thin films deposition by pulsed laser ablation on Pb substrates. • Characterization of nanomechanical properties of Nb thin films. • Characterization of electrical properties of Nb thin films.

  4. Nondestructive Encapsulation of CdSe/CdS Quantum Dots in an Inorganic Matrix by Pulsed Laser Deposition.

    Science.gov (United States)

    Aubret, Antoine; Houel, Julien; Pereira, Antonio; Baronnier, Justine; Lhuillier, Emmanuel; Dubertret, Benoit; Dujardin, Christophe; Kulzer, Florian; Pillonnet, Anne

    2016-08-31

    We report the successful encapsulation of colloidal quantum dots in an inorganic matrix by pulsed laser deposition. Our technique is nondestructive and thus permits the incorporation of CdSe/CdS core/shell colloidal quantum dots in an amorphous yttrium oxide matrix (Y2O3) under full preservation of the advantageous optical properties of the nanocrystals. We find that controlling the kinetic energy of the matrix precursors by means of the oxygen pressure in the deposition chamber facilitates the survival of the encapsulated species, whose well-conserved optical properties such as emission intensity, luminescence spectrum, fluorescence lifetime, and efficiency as single-photon emitters we document in detail. Our method can be extended to different types of nanoemitters (e.g., nanorods, dots-in-rods, nanoplatelets) as well as to other matrices (oxides, semiconductors, metals), opening up new vistas for the realization of fully inorganic multilayered active devices based on colloidal nano-objects.

  5. N-doped ZnO films grown from hybrid target by the pulsed laser deposition technique

    Science.gov (United States)

    Martín-Tovar, E. A.; Chan y Díaz, E.; Acosta, M.; Castro-Rodríguez, R.; Iribarren, A.

    2016-10-01

    ZnO thin films were grown by the pulsed laser deposition technique on glass substrate using a hybrid target composed of ZnO powder embedded into a poly(ethyl cyanoacrylate) matrix. The resulting thin film presented ZnO wurtzite structure with very low stress and diffractogram very similar to that of the powder pattern. From comparing with ZnO thin films grown from traditional sintered target, it is suggested that the use of this hybrid target with a soft matrix led to ejection of ZnO clusters that conveniently disposed and adhered to substrate and previous deposited layers. Chemical measurements showed the presence of Zn-N bonds, besides Zn-O ones. Optical absorption profile confirmed the presence of low-polymerized zinc oxynitride molecular subunits, besides ZnO.

  6. Characterization of perovskite film prepared by pulsed laser deposition on ferritic stainless steel using microscopic and optical methods

    Science.gov (United States)

    Durda, E.; Jaglarz, J.; Kąc, S.; Przybylski, K.; El Kouari, Y.

    2016-06-01

    The perovskite La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF48) film was deposited on Crofer 22 APU ferritic stainless steel by pulsed laser deposition (PLD). Morphological studies of the sample were performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Information about film thickness and surface topography of the film and the steel substrate were obtained using following optical methods: spectroscopic ellipsometry (SE), bidirectional reflection distribution function (BRDF) and total integrated reflectometry (TIS). In particular, the BRDF study, being complementary to atomic force microscopy, yielded information about surface topography. Using the previously mentioned methods, the following statistic surface parameters were determined: root-mean square (rms) roughness and autocorrelation length by determining the power spectral density (PSD) function of surface irregularities.

  7. LiCoO{sub 2} thin films grown by pulsed laser deposition on low cost substrates

    Energy Technology Data Exchange (ETDEWEB)

    Ginley, D.S.; Perkins, J.D.; McGraw, J.M.; Parilla, P.A.

    1998-07-01

    The authors report on the use of pulsed laser deposition (PLD) to grow thin films of LiCoO{sub 2} on a number of low cost substrates including SnO{sub 2} coated Upilex, stainless steel and SnO{sub 2} coated glass. Highly textured (001) films grown on CVD deposited SnO{sub 2} films on 7059 glass, were obtained at 200 to 500 mTorr O{sub 2} and a temperature of 500 C. Similar texture was not obtained on the stainless or Upilex however dense films from crystalline to amorphous were obtained. The films were characterized by x-ray diffraction and Raman spectroscopy.

  8. Annealing effects on the structural and electrical properties of pulsed laser deposited BaPbO3 thin films

    Science.gov (United States)

    Satish, B.; Jayaraj, M. K.

    2014-01-01

    Conductive pervoskite BaPbO3 (BPO) films as potential electrodes for ferroelectric / tuneable applications were prepared by pulsed laser deposition technique at 600°C and at 0.1 mbar oxygen partial pressure on fused silica substrates. The structural and electrical properties of the films showed a dependence on annealing temperatures and the high oxygen ambient. XRD and standard four probe method with Hall setup were employed to investigate the dependence of growth conditions on crystal structure, resistivity and the carrier concentration on annealing the BPO thin films. The surface topography was analysed by AFM. The unannealed as deposited films showed the least resistivity of 1.6 × 10-2 ohm cm and a bandgap of 4.1eV.

  9. Effects of nitrogen on the growth and optical properties of ZnO thin films grown by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Cui, J B; Thomas, M A; Soo, Y C; Kandel, H; Chen, T P [Department of Physics and Astronomy, University of Arkansas at Little Rock, Little Rock, AR 72204 (United States)

    2009-08-07

    ZnO thin films were grown using pulsed laser deposition by ablating a Zn target in various mixtures of O{sub 2} and N{sub 2}. The presence of N{sub 2} during deposition was found to affect the growth of the ZnO thin films and their optical properties. Small N{sub 2} concentrations during growth led to strong acceptor-related photoluminescence (PL), while larger concentrations affected both the intensity and temperature dependence of the emission peaks. In addition, the PL properties of the annealed ZnO thin films are associated with the N{sub 2} concentration during their growth. The possible role of nitrogen in ZnO growth and annealing is discussed.

  10. Structural and optical properties of Cu-doped CdTe films with hexagonal phase grown by pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    F. de Moure-Flores

    2012-06-01

    Full Text Available Cu-doped CdTe thin films were prepared by pulsed laser deposition on Corning glass substrates using powders as target. Films were deposited at substrate temperatures ranging from 100 to 300 °C. The X-ray diffraction shows that both the Cu-doping and the increase in the substrate temperature promote the presence of the hexagonal CdTe phase. For a substrate temperature of 300 °C a CdTe:Cu film with hexagonal phase was obtained. Raman and EDS analysis indicate that the films grew with an excess of Te, which indicates that CdTe:Cu films have p-type conductivity.

  11. Effects of Annealing Temperature on Properties of ZnO Thin Films Grown by Pulsed Laser Deposition

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Hui-zhao; XUE Shou-bin; XUE Cheng-shan; HU Li-jun; LI Bao-li; ZHANG Shi-ying

    2007-01-01

    ZnO thin films are deposited on n-Si(111) substrates by pulsed laser deposition(PLD) system.Then the samples are annealed at different temperatures in air ambient and their properties are investigated particularly as a function of annealing temperature.The microstructure,morphology and optical properties of the as-grown ZnO films are studied by X-ray diffraction(XRD),atomic force microscope(AFM),Fourier transform infrared spectroscopy(FTIR) and photoluminescence(PL) spectra.The results show that the as-grown ZnO films have a hexagonal wurtzite structure with a preferred c-axis orientation.Moreover,the diameters of the ZnO crystallites become larger and the crystal quality of the ZnO films is improved with the increase of annealing temperature.

  12. The growth of nanostructured Cu{sub 2}ZnSnS{sub 4} films by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Che Sulaiman, Nurul Suhada; Nee, Chen Hon [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Yap, Seong Ling [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Lee, Yen Sian [UM Power Energy Dedicated Advanced Centre (UMPEDAC), University of Malaya, 50603 Kuala Lumpur (Malaysia); Tou, Teck Yong [Faculty of Engineering, Multimedia University, 63100 Cyberjaya, Selangor (Malaysia); Yap, Seong Shan, E-mail: seongshan@gmail.com [UM Power Energy Dedicated Advanced Centre (UMPEDAC), University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-11-01

    Highlights: • Nanostructured CZTS films were grown at room temperature by using 355 nm laser. • CZTS films with E{sub g} of 1.9 eV have been obtained at 2 J cm{sup −2} at room temperature. • At high fluence, Cu/Sn rich droplets affected the overall quality of the films. • Improved crystallinity and E{sub g} of 1.5 eV was obtained at substrate temperature as low as 100 °C. - Abstract: In this work, we investigated on the growth of Cu{sub 2}ZnSnS{sub 4} films by using pulsed Nd:YAG laser (355 nm) ablation of a quaternary Cu{sub 2}ZnSnS{sub 4} target. Depositions were performed at laser fluence from 0.5 to 4 J cm{sup −2}. The films were grown at substrate temperature from 27 °C to 300 °C onto glass and silicon substrates. The dependence of the film morphology, composition, and optical properties are studied and discussed with respect to laser fluence and substrate temperature. Composition analysis from energy dispersive X-ray spectral results show that CZTS films with composition near stoichiometric were obtained at an optimized fluence at 2 J cm{sup −2} by 355 nm laser where the absorption coefficient is >10{sup 4} cm{sup −1}, and optical band gap from a Tauc plot was ∼1.9 eV. At high fluence, Cu and Sn rich droplets were detected which affect the overall quality of the films. The presence of the droplets was associated to the high degree of preferential and subsurface melting on the target during high fluence laser ablation. Crystallinity and optical band gap (1.5 eV) were improved when deposition was performed at substrate temperature of 100 °C.

  13. In-situ fabrication of Y-Ba-Cu oxide thin films by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, R.M.; Ferguson, A.L.; Pegrum, C.M. (Strathclyde Univ., Glasgow (United Kingdom). Dept. of Applied Physics)

    1991-03-01

    This paper reports the in-situ deposition of laser-ablated YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} films on MgO substrates, using the third and second harmonics of a Nd-YAG laser. The authors investigate the conditions needed during post-deposition oxygenation to produce the best films. The authors highly-oriented samples are made using the third harmonic (wavelength {lambda} = 355 nm) on {l angle}100{r angle} MgO and have a transition temperature T{sub c} of 85K, a critical current density J{sub c} of 1.5 {times} 10{sup 5} A/cm{sup 2} at 4.2 K. Films made with the second harmonic on MgO are, as expected, markedly poorer in quality. Highly-oriented films have also been made on {l angle}110{r angle} and {l angle}100{r angle} SrTiO{sub 3} with {lambda} = 355 nm.

  14. Pulsed laser deposited Ag nanoparticles on nickel hydroxide nanosheet arrays for highly sensitive surface-enhanced Raman scattering spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Yuting; Wang, Huanwen; Chen, Xiao [Department of Chemistry, Tongji University, Shanghai 200092 (China); Wang, Xuefeng, E-mail: xfwang@tongji.edu.cn [Department of Chemistry, Tongji University, Shanghai 200092 (China); Wei, Huige [Integrated Composites Laboratory (ICL), Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, Texas 77710 (United States); Guo, Zhanhu, E-mail: zhanhu.guo@lamar.edu [Integrated Composites Laboratory (ICL), Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, Texas 77710 (United States)

    2014-10-15

    Highlights: • Silver nanoparticles (NPs) were deposited on nickel hydroxide nanosheet (NS) arrays by pulsed laser deposition (PLD) for surface-enhanced Raman scattering (SERS) spectroscopy. • The Ag/Ni(OH){sub 2} composite film exhibits very high Raman scattering enhancement ability, possessing an enhancement factor as high as 5 × 10{sup 6}. • The enhancement ability of the substrate was strongly dependent on the size and interparticle gap of Ag NPs. • The 3D structure of Ni(OH){sub 2} NS arrays and the charge transfer of Ag NPs may be responsible for this high sensitivity Raman phenomenon. - Abstract: In the present work, silver nanoparticles (NPs) were deposited on nickel hydroxide nanosheet (NS) arrays by pulsed laser deposition (PLD) for surface-enhanced Raman scattering (SERS) spectroscopy. The effective high specific surface area with silver NPs decorated on the NS arrays was revealed by field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The microstructure and optical property of this three-dimensional (3D) substrate were investigated by X-ray diffraction (XRD) and UV–vis spectra, respectively. Using rhodamine 6G (R6G) as probe molecules with the concentration down to 10{sup −5} M, the Ag/Ni(OH){sub 2} composite film exhibits very high Raman scattering enhancement ability, possessing an enhancement factor as high as 5 × 10{sup 6}. It has been found that the enhancement ability of the substrate was strongly dependent on the size and interparticle gap of Ag NPs rather than the testing position on the film surface. In addition, the 3D structure of Ni(OH){sub 2} NS arrays and the charge transfer of Ag NPs may be responsible for this high sensitivity Raman phenomenon.

  15. Enhancing the photoelectrochemical response of TiO2 nanotubes through their nanodecoration by pulsed-laser-deposited Ag nanoparticles

    Science.gov (United States)

    Trabelsi, K.; Hajjaji, A.; Gaidi, M.; Bessais, B.; El Khakani, M. A.

    2017-08-01

    We report on the pulsed laser deposition (PLD) based nanodecoration of titanium dioxide (TiO2) nanotube arrays (NTAs) by Ag nanoparticles (NPs). We focus here on the investigation of the effect of the number of laser ablation pulses (NLP) of the silver target on both the average size of the Ag-NPs and the photoelectrochemical conversion efficiency of the Ag-NP decorated TiO2-NT based photoanodes. By varying the NLP, we were able to not only control the size of the PLD-deposited Ag nanoparticles from 20 to ˜50 nm, but also to increase concomitantly the surface coverage of the TiO2 NTAs by Ag-NPs. The red-shifting of the surface plasmon resonance peak of the PLD-deposited Ag-NPs deposited onto quartz substrates confirmed the increase of their size as the NLP is increased from 500 to 10 000. By investigating the photo-electrochemical properties of Ag-NP decorated TiO2-NTAs, by means of linear sweep cyclic voltammetry under UV-Vis illumination, we found that the generated photocurrent is sensitive to the size of the Ag-NPs and reaches a maximum value at NLP =500 (i.e.,; Ag-NP size of ˜20 nm). For NLP = 500, the photoconversion efficiency of the Ag-NP decorated TiO2-NTAs is shown to reach a maximum of 4.5% (at 0.5 V vs Ag/AgCl). The photocurrent enhancement of Ag-NP decorated TiO2-NTAs is believed to result from the additional light harvesting enabled by the ability of Ag-NPs to absorb visible irradiation caused by various localized surface plasmon resonances, which in turn depend on the size and interdistance of the Ag nanoparticles.

  16. Hydroxyapatite thin films synthesized by pulsed laser deposition and magnetron sputtering on PMMA substrates for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Socol, G. [National Institute for Lasers, Plasma, and Radiation Physics, Atomistilor Street 409, RO-77125 Magurele, Ilfov (Romania); Macovei, A.M. [Institute of Biochemistry, Romanian Academy, Splaiul Independentei 296, 060031 Bucharest (Romania); Miroiu, F.; Stefan, N.; Duta, L.; Dorcioman, G. [National Institute for Lasers, Plasma, and Radiation Physics, Atomistilor Street 409, RO-77125 Magurele, Ilfov (Romania); Mihailescu, I.N., E-mail: ion.mihailescu@inflpr.ro [National Institute for Lasers, Plasma, and Radiation Physics, Atomistilor Street 409, RO-77125 Magurele, Ilfov (Romania); Petrescu, S.M. [Institute of Biochemistry, Romanian Academy, Splaiul Independentei 296, 060031 Bucharest (Romania); Stan, G.E.; Marcov, D.A. [National Institute of Materials Physics, 105 bis Atomistilor Street, RO-77125 Bucharest-Magurele (Romania); Chiriac, A.; Poeata, I. [' Prof. Dr. N. Oblu' , Emergency Clinical Hospital, Neurosurgery Department, Ateneului Street, 3, 700309 Iasi (Romania)

    2010-05-25

    Functionalized implants represent an advanced approaching in implantology, aiming to improve the biointegration and the long-term success of surgical procedures. We report on the synthesis of hydroxyapatite (HA) thin films on polymethylmetacrylate (PMMA) substrates - used as cranio-spinal implant-type structures - by two alternative methods: pulsed laser deposition (PLD) and radio-frequency magnetron sputtering (MS). The deposition parameters were optimized in order to avoid the substrate overheating. Stoichiometric HA structures were obtained by PLD with incident laser fluences of 1.4-2.75 J/cm{sup 2}, pressures of 30-46.66 Pa and 10 Hz pulses repetition rate. The MS depositions were performed at constant pressure of 0.3 Pa in inert and reactive atmospheres. SEM-EDS, XRD, FTIR and pull-out measurements were performed assessing the apatitic-type structure of the prepared films along with their satisfactory mechanical adhesion. Cell viability, proliferation and adhesion tests in osteosarcoma SaOs2 cell cultures were performed to validate the bioactive behaviour of the structures and to select the most favourable deposition regimes. For PLD, this requires a low fluence of 1.4 J/cm{sup 2}, reduced pressure of water vapours and a 100 {sup o}C/4 h thermal treatment. For MS, the best results were obtained for 80% Ar + 20% O{sub 2} reactive atmosphere at low RF power ({approx}75 W). Cells grown on these coatings exhibit behaviour similar to those grown on the standard borosilicate glass control: increased viability, good proliferation, and optimal cell adhesion. In vitro tests proved that HA/PMMA neurosurgical structures prepared by PLD and MS are compatible for the interaction with human bone cells.

  17. Adhesion of fibroblasts on micro- and nanostructured surfaces prepared by chemical vapor deposition and pulsed laser treatment

    Energy Technology Data Exchange (ETDEWEB)

    Veith, M; Aktas, O C; Ullah Wazir, H; Grobelsek, I [INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbruecken (Germany); Metzger, W; Sossong, D; Pohlemann, T; Oberringer, M [Department of Trauma-, Hand- and Reconstructive Surgery, Saarland University, Kirrberger Strasse, Building 57, 66421 Homburg (Germany); Puetz, N; Wennemuth, G, E-mail: Michael.Veith@inm-gmbh.d [Department of Anatomy and Cell Biology, Saarland University, Kirrberger Strasse, Building 61, 66421 Homburg (Germany)

    2010-09-15

    The development of micro- and nanostructured surfaces which improve the cell-substrate interaction is of great interest in today's implant applications. In this regard, Al/Al{sub 2}O{sub 3} bi-phasic nanowires were synthesized by chemical vapor deposition of the molecular precursor ({sup t}BuOAlH{sub 2}){sub 2}. Heat treatment of such bi-phasic nanowires with short laser pulses leads to micro- and nanostructured Al{sub 2}O{sub 3} surfaces. Such surfaces were characterized by scanning electron microscopy (SEM), electron dispersive spectroscopy and x-ray photoelectron spectroscopy. Following the detailed material characterization, the prepared surfaces were tested for their cell compatibility using normal human dermal fibroblasts. While the cells cultivated on Al/Al{sub 2}O{sub 3} bi-phasic nanowires showed an unusual morphology, cells cultivated on nanowires treated with one and two laser pulses exhibited morphologies similar to those observed on the control substrate. The highest cell density was observed on surfaces treated with one laser pulse. The interaction of the cells with the nano- and microstructures was investigated by SEM analysis in detail. Laser treatment of Al/Al{sub 2}O{sub 3} bi-phasic nanowires is a fast and easy method to fabricate nano- and microstructured Al{sub 2}O{sub 3}-surfaces for studying cell-surface interactions. It is our goal to develop a biocompatible Al{sub 2}O{sub 3}-surface which could be used as a coating material for medical implants exhibiting a cell selective response because of its specific physical landscape and especially because it promotes the adhesion of osteoblasts while minimizing the adhesion of fibroblasts.

  18. Post-deposition cooling in oxygen is critical for YBa sub 2 Cu sub 3 O sub 7 sub - sub d films deposited by eclipse pulsed laser deposition method

    CERN Document Server

    Ohmukai, M; Ohno, T

    2001-01-01

    YBa sub 2 Cu sub 3 O sub 7 sub - sub d thin films were deposited on MgO single crystals by means of an eclipse pulsed laser deposition method. Deposited films are cooled down in situ under an oxygen atmosphere at a given oxygen pressure. The relationship between critical temperature and oxygen deficiency was investigated by means of electrical resistance R(T) and X-ray diffraction measurements. Post- deposition cooling is critical and the high pressure of oxygen during cooling is favorable.

  19. Pulsed laser deposited indium tin oxides as alternatives to noble metals in the near-infrared region.

    Science.gov (United States)

    Fang, Xu; Mak, C L; Zhang, Shiyu; Wang, Zhewei; Yuan, Wenjia; Ye, Hui

    2016-06-08

    Transparent conductive indium tin oxide thin films with thickness around 200 nm were deposited on glass substrates by pulsed laser deposition technology. The microstructure and the electrical and optical properties of the ITO films deposited under different oxygen pressures and substrate temperatures were systematically investigated. Distinct different x-ray diffraction patterns revealed that the crystallinity of ITO films was highly influenced by deposition conditions. The highest carrier concentration of the ITO films was obtained as 1.34  ×  10(21) cm(-3) with the lowest corresponding resistivity of 2.41  ×  10(-4) Ω cm. Spectroscopic ellipsometry was applied to retrieve the dielectric permittivity of the ITO films to estimate their potential as plasmonic materials in the near-infrared region. The crossover wavelength (the wavelength where the real part of the permittivity changes from positive to negative) of the ITO films exhibited high dependence on the deposition conditions and was optimized to as low as 1270 nm. Compared with noble metals (silver or gold etc), the lower imaginary part of the permittivity (<3) of ITO films suggests the potential application of ITO in the near-infrared range.

  20. In situ Pulsed Laser Deposition of C-Axis Oriented MgB2 Films and Their Characterization

    Science.gov (United States)

    Shinde, Sanjay; Lakew, Brook; Ogale, S. B.; Kulkarni, V. N.; Kale, S. N.; Venkatesan, T.

    2004-01-01

    The recent discovery of an intermetallic superconductor MgB2 has renewed interest in the area of superconductivity not only because of fundamental understanding of superconductivity but also due to its potential applicability in devices such as thermal detectors. Considerable amount of research has been devoted to obtain MgB2 films by an all in situ growth technique. We have grown MgB2 thin films by an all in situ pulsed laser deposition process from pure B and Mg targets. Ultrathin layers of B and Mg were deposited in a multilayer configuration. Hundreds of such Mg-B bilayers with a capping Mg layer on the top were deposited on sapphire substrate. These depositions were done in high vacuum (approx. 10(exp -7) Torr) and at room temperature. After deposition, such a configuration was annealed at high temperature for a short time in a forming gas (4% H2 in Ar). The best films, obtained by this procedure, showed superconducting transition temperature approx. 30 K. These films have been characterized by x-ray diffraction, Rutherford Backscattering Spectrometry, AC susceptibility-, resistivity- (with and without magnetic field) and 1/f noise-measurements. The physical properties of these films will be presented and discussed.

  1. Channeling and resonant backscattering investigations of Co doped diluted magnetic oxide films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, V.N. E-mail: vnk@iitk.ac.in; vnk@squid.umd.edu; Shinde, S.R.; Zhao, Y.G.; Choudhary, R.J.; Ogale, S.B.; Greene, R.L.; Venkatesan, T

    2004-06-01

    We present the results of ion channeling and 3.045 MeV He{sup +} oxygen resonant backscattering along with the results of magnetic and electric characterization experiments performed on thin films of Co doped TiO{sub 2} and La{sub 0.5}Sr{sub 0.5}TiO{sub 3} oxides deposited on (0 0 1) LaAlO{sub 3} substrates using the pulsed laser deposition technique. These films exhibit Curie temperature well above 300 K and hence offer potential use for spintronic devices. In the case of Co doped TiO{sub 2} films the magnetic data have been understood in the light of channeling results, which showed non-substitutionality of Co atoms for the films deposited at 700 deg. C, and their incorporation in the matrix by either annealing at a higher temperature of 875 deg. C or deposition at this temperature. In the case of the Co doped La{sub 0.5}Sr{sub 0.5}TiO{sub 3}, the resistivity data for the films deposited at different oxygen pressures correlate well with the oxygen contents of the films obtained by resonant backscattering.

  2. Growth and thermoelectric properties of FeSb2 films produced by pulsed laser deposition

    DEFF Research Database (Denmark)

    Canulescu, Stela; SUN, Ye; Schou, Jørgen

    FeSb2, a strongly correlated semiconductor, has promising application potential for thermoelectric cooling at cryogenic temperatures [1,2]. Single crystals of FeSb2 were found to exhibit colossal thermopower (S) values up to ~ −45000 μVK-1 and record high power factors up to 2300 μWK−2 cm−1 at 12 K...... enhanced thermoelectric performance. Herein, FeSb2 films were produced on silica substrates in a low-pressure Ar environment by a pulsed Nd:YAG laser at 355 nm. The effect of growth parameters, such as substrate temperature, Ar pressure, incident fluence and growth time, on the PLD growth of FeSb2...

  3. Structural transformations in MoO{sub x} thin films grown by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Camacho-Lopez, M.A.; Haro-Poniatowski, E. [Departamento de Fisica, Laboratorio de Optica Cuantica, Universidad Autonoma Metropolitana Iztapalapa, Apdo. Postal 55-534, 09340, Mexico D. F. (Mexico); Escobar-Alarcon, L. [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, 11801, Mexico D. F. (Mexico)

    2004-01-01

    In this work, laser-induced crystallization in MoO{sub x} thin films (1.8{<=}x{<=}2.1) is reported. This transformation involves a MoO{sub x} oxidation and subsequently a crystallization process from amorphous MoO{sub 3} to crystalline {alpha}MoO{sub 3}. For comparison purposes crystallization is induced thermally, in an oven, as well. The crystallization kinetics is monitored by Raman spectroscopy; a threshold in the energy density necessary to induce the phase transformation is determined in the case of photo-crystallization. This threshold depends on the type of substrate on which the film is deposited. For the thin films deposited on glass substrates, the structural transformation is from amorphous MoO{sub x} to the thermodynamically stable {alpha}MoO{sub 3} crystalline phase. For the thin films deposited on Si(100) the structural transformation is from amorphous MoO{sub x} to a mixture of {alpha}MoO{sub 3} and the thermodynamically unstable {beta}MoO{sub 3} crystalline phases. The structural transformations are also characterized by scanning electron microscopy and light-transmission experiments. (orig.)

  4. Growth and characterization of ternary Ni, Mg–Al and Ni–Al layered double hydroxides thin films deposited by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Birjega, R. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Vlad, A., E-mail: angela.vlad@gmail.com [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Matei, A.; Ion, V.; Luculescu, C.; Dinescu, M. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Str., Magurele, 76900 Bucharest (Romania); Zavoianu, R. [University of Bucharest, Faculty of Chemistry, Department of Chemical Technology and Catalysis, 4-12 Regina Elisabeta Bd., Bucharest (Romania)

    2016-09-01

    Layered double hydroxides (LDHs) are a class of layered materials consisting of positively charged brucite-like layers and exchangeable interlayer anions. Layered double hydroxides containing a transition metal which undergoes a reversible redox reaction in the useful potential range have been proposed as electrode coating materials due to their properties of charge transport and redox catalysts in basic solutions. Ni–Al,(Ni,Mg)–Al and, as reference, non-electronically conductive Mg–Al double hydroxides thin films were obtained via pulsed laser deposition technique. The thin films were deposited on different substrates (Si, glass) by using a Nd:YAG laser (1064 nm) working at a repetition rate of 10 Hz. X-ray diffraction, Atomic Force Microscopy, Energy Dispersive X-ray spectroscopy, Fourier Transform Infra-Red Spectroscopy, Secondary Ions Mass Spectrometry, Impedance Analyzer and ellipsometry were the techniques used for the as deposited thin films investigation. The optical properties of Ni based LDH thin films and the effect of the Ni amount on the structural, morphological and optical response are evidenced. The optical band gap values, covering a domain between 3.84 eV and 4.38 eV, respond to the Ni overall concentration: the higher Ni amount the lower the band gap value. - Highlights: • Ternary Ni, Mg–Al and Ni–Al layered double hydroxides thin films were deposited. • The effect of the nickel is evidenced. • The possibility to tailor the materials accompanied by an optical response is shown.

  5. Growth of strained ZnSe layers on GaAs substrates by pulsed laser deposition carried out in an off-axis deposition geometry

    Energy Technology Data Exchange (ETDEWEB)

    Ganguli, Tapas [Raja Ramanna Centre for Advanced Technology, Indore, 452 013 (India)], E-mail: tapas@cat.ernet.in; Porwal, Sanjay; Sharma, Tarun; Ingale, Alka; Kumar, Shailendra; Tiwari, Pragya [Raja Ramanna Centre for Advanced Technology, Indore, 452 013 (India); Balamurugan, A.K.; Rajagopalan, S.; Tyagi, A.K. [Materials Science Division, IGCAR, Kalpakkam 603 102 (India); Chandrasekaran, K.S.; Arora, B.M. [Department of Condensed Matter Physics and Materials Science, TIFR, Mumbai 400 005 (India); Rustagi, K.C. [Department of Physics, IIT, Powai, Mumbai 400 076 (India)

    2007-07-31

    We have deposited thin layers of ZnSe on (001) oriented GaAs substrates by pulsed laser deposition at different incident laser fluence (referred to as normal geometry) and in an off-axis geometry where the plasma plume direction is at an angle of {approx} 25{sup o} away from the direction of the substrate. The crystalline quality of these layers has been studied by high-resolution X-ray diffraction measurements and Raman scattering. We find that we are in a position to deposit pseudomorphic strained layers of ZnSe on GaAs in the off-axis deposition geometry when the ZnSe layer thickness is less than the critical thickness of ZnSe on GaAs i.e. 150 nm. Secondary ion mass spectroscopy, scanning electron microscopy, photoluminescence and electrical transport measurements have also been carried out in all the ZnSe layers and the results of all the above characterizations have been compared for the normal geometry and the off-axis geometry of deposition. All the results indicate that the ZnSe layers deposited in the off-axis geometry have better crystalline quality and an improved interface as compared to the ones deposited in the normal geometry. We attribute this improvement in the overall quality of the ZnSe layers in the off-axis geometry to the reduction in the average energy of the plume particles that reach the GaAs substrate in the off-axis geometry.

  6. Pulsed laser deposition of the lysozyme protein: an unexpected “Inverse MAPLE” process

    DEFF Research Database (Denmark)

    Schou, Jørgen; Matei, Andreea; Constantinescu, Catalin

    2012-01-01

    the ejection and deposition of lysozyme. This can be called an “inverse MAPLE” process, since the ratio of “matrix” to film material in the target is 10:90, which is inverse of the typical MAPLE process where the film material is dissolved in the matrix down to several wt.%. Lysozyme is a well-known protein...... which is used in food processing and is also an important constituent of human secretions such as sweat and saliva. It has a well-defined mass (14307 u) and can easily be detected by mass spectrometric methods such as MALDI (Matrix-assisted laser desorption ionization) in contrast to many other organic...

  7. Pulsed laser deposition of the lysozyme protein: an unexpected “Inverse MAPLE” process

    DEFF Research Database (Denmark)

    Schou, Jørgen; Matei, Andreea; Constantinescu, Catalin

    2012-01-01

    the ejection and deposition of lysozyme. This can be called an “inverse MAPLE” process, since the ratio of “matrix” to film material in the target is 10:90, which is inverse of the typical MAPLE process where the film material is dissolved in the matrix down to several wt.%. Lysozyme is a well-known protein...... which is used in food processing and is also an important constituent of human secretions such as sweat and saliva. It has a well-defined mass (14307 u) and can easily be detected by mass spectrometric methods such as MALDI (Matrix-assisted laser desorption ionization) in contrast to many other organic...... materials. Also, the thermal properties of lysozyme, including the heat-induced decomposition behavior are comparatively well-known. The ablation of lysozyme from a dry pressed target in vacuum was measured by weight loss in nanosecond laser ablation at 355 with a fluence of 0.5 to 6 J/cm2. Films...

  8. Optical and microwave properties of CaBi4Ti4O15 ferroelectric thin films deposited by pulsed laser deposition

    Science.gov (United States)

    Emani, Sivanagi Reddy; Joseph, Andrews; Raju, K. C. James

    2016-05-01

    Transparent CaBi4Ti4O15 (CBTi) ferroelectric thin films are deposited by pulsed laser deposition method. The structural, optical and microwave dielectric properties were investigated. CBTi thin films had polycrystalline bismuth-layered perovskite structure and exhibited excellent optical properties. The X-ray analysis of the thin film demonstrates the phase formation and crystallinity. The optical transmission studies show that film is transparent in VIS-NIR region with a direct band gap of 3.53 EV. Morphological studies provide surface roughness as 3 mm. Dielectric constant and loss factors were 48 and 0.060 respectively, at 10GHz. These results suggest that CBTi thin films are promising multifunctional materials for applications in optoelectronic and microwave devices.

  9. Improving the uncommon (110) growing orientation of Al-doped ZnO thin films through sequential pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Coman, Tudor [Faculty of Physics, “Al. I. Cuza” University, 11 Carol I Blvd., Iasi 700506 (Romania); Ursu, Elena Laura [Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, Iasi 700487 (Romania); Nica, Valentin; Tiron, Vasile [Faculty of Physics, “Al. I. Cuza” University, 11 Carol I Blvd., Iasi 700506 (Romania); Olaru, Mihaela; Cotofana, Corneliu [Polymer Materials Physics Laboratory, “Petru Poni” Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, Iasi 700487 (Romania); Dobromir, Marius [Faculty of Physics, “Al. I. Cuza” University, 11 Carol I Blvd., Iasi 700506 (Romania); Coroaba, Adina [Centre of Advanced Research in Bionanoconjugates and Biopolymers, “Petru Poni” Institute of Macromolecular Chemistry, 41 A Grigore Ghica Voda Alley, Iasi 700487 (Romania); Dragos, Oana-Georgiana; Lupu, Nicoleta [National Institute of Research and Development for Technical Physics, 47 Mangeron Blvd., Iasi 700050 (Romania); Caltun, Ovidiu Florin [Faculty of Physics, “Al. I. Cuza” University, 11 Carol I Blvd., Iasi 700506 (Romania); Ursu, Cristian, E-mail: cristian.ursu@icmpp.ro [Polymer Materials Physics Laboratory, “Petru Poni” Institute of Macromolecular Chemistry, 41 A Gr. Ghica Voda Alley, Iasi 700487 (Romania)

    2014-11-28

    High quality Al-doped ZnO (AZO) films with uncommon (110) orientation are obtained on amorphous substrate by using Sequential Pulsed Laser Deposition technique. The dependence of the structural, optical and electrical properties with dopant concentration and oxygen deposition pressure was investigated systematically. We note a transition from the (002) preferential orientation of crystallites to an uncommon (110) orientation due to a combined effect of doping concentration and deposition pressure decreasing. For constant deposition pressure of 5 Pa the film crystallinity is changed from preferential (002) to polycrystalline when increasing dopant concentration. For the maximum dopant concentration that we have investigated (i.e., 4.4% at.) structural properties of AZO films are changed from a polycrystalline phase to a (110) preferential orientation when the deposition pressure decreases. This uncommon growth mode is accompanied by a change of the morphology from a densely packed granular structure to a more rarefied one. Moreover, the band gap widens up to 3.88 eV and the electrical resistivity drops to 5.4 × 10{sup −2} Ω cm. The structural changes were attributed to two mechanisms: a first one, responsible for the (002) phase suppression as a consequence of aluminum ion bombardment during the doping process and, a second one, in charge with (110) phase growth as the diffusion rates of zinc and oxygen atoms are affected by the dopant incorporation and by the decrease of deposition pressure. - Highlights: • Sequential PLD (SPLD) of (110) Al-doped ZnO thin films on amorphous substrate • Highly c-axis oriented films with high transparency and low resistivity • Fine tuning of the dopant concentration through SPLD method.

  10. Fabrication of nanowires of Al-doped ZnO using nanoparticle assisted pulsed laser deposition (NAPLD) for device applications

    Energy Technology Data Exchange (ETDEWEB)

    Thanka Rajan, S. [ECMS Division, CSIR – Central Electrochemical Research Institute, Karaikudi 630 006 (India); Subramanian, B., E-mail: subramanianb3@gmail.com [ECMS Division, CSIR – Central Electrochemical Research Institute, Karaikudi 630 006 (India); Nanda Kumar, A.K.; Jayachandran, M. [ECMS Division, CSIR – Central Electrochemical Research Institute, Karaikudi 630 006 (India); Ramachandra Rao, M.S. [Department of Physics, Indian Institute of Technology Madras, Chennai 600 036 (India)

    2014-01-25

    Graphical abstract: -- Highlights: • Novel technique of NP assisted PLD was employed to obtain Al doped ZnO. • AZO nano wires with aspect ratios exceeding 20 were obtained at 500 sccm Ar gas pressure. • AZO films belong to the most stable wurtzite type. • Films show near band edge emission and defect related emission. -- Abstract: Aluminium doped zinc oxide (AZO) nanostructures have been successfully synthesized on sapphire substrates by using nanoparticle assisted pulsed laser deposition (NAPLD) in Ar atmosphere without using any catalyst. The growth of the AZO nanowires has been investigated by varying the argon flow rates. The coatings have been characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Atomic force microscopy (AFM), Diffuse Reflectance Spectroscopy (DRS), Laser Raman spectroscopy and Photoluminescence spectroscopy. The results of XRD indicate that the deposited films are crystalline ZnO with hexagonal wurtzite structure with (0 0 2) preferred orientation. FESEM images also clearly reveal the hexagonal structure and the formation of nanowires with aspect ratios between 15 and 20. The surface roughness value of 9.19 nm was observed from AFM analysis. The optical properties of the sample showed that under excitation with λ = 325 nm, an emission band was observed in UV and visible region. The characteristic Raman peaks were detected at 328, 380, 420, 430 cm{sup −1}.

  11. Room-temperature deposition of nanocrystalline PbWO 4 thin films by pulsed laser ablation

    Science.gov (United States)

    Ryu, J. H.; Yoon, J.-W.; Shim, K. B.; Koshizaki, N.

    2006-07-01

    Pulsed laser ablation (PLA) was applied to synthesize nanocrystalline PbWO4 thin films onto glass substrates. The effects of Ar background gas pressure on phase evolution, microstructures and optical characteristics of PbWO4 thin films were investigated in detail. The PLA processes were carried out at room temperature without substrate heating or post-annealing treatment. XRD and HR-TEM results revealed that the PbWO4 thin films are composed of nanocrystalline and amorphous phases. Moreover, the films contained a high density of lattice defects such as twin boundaries and edge dislocations. The crystallite size and crystallinity increased, which were associated with a change in surface morphology as the Ar pressure increased. Reduced tungsten states W5+ or W4+ induced by oxygen vacancies were observed at 10 Pa and the atomic concentration of all constituent element was almost stoichiometric, especially the [Pb]/[W] ratio, which was nearly unity above 50 Pa. The optical energy band-gap was 3.03 eV at 50 Pa and increased to 3.35 eV at 100 Pa, which are narrower than the reported value (4.20 eV). This optical band-gap narrowing could be attributed to localized band-tail states and new energy levels induced by the amorphous structure and inherent lattice defects.

  12. Advantageous use of metallic cobalt in the target for pulsed laser deposition of cobalt-doped ZnO films

    Science.gov (United States)

    Ying, Minju; Blythe, Harry J.; Dizayee, Wala; Heald, Steve M.; Gerriu, Fatma M.; Fox, A. Mark; Gehring, Gillian A.

    2016-08-01

    We investigate the magnetic properties of ZnCoO thin films grown by pulsed laser deposition (PLD) from targets made containing metallic Co or CoO precursors instead of the usual Co3O4. We find that the films grown from metallic Co precursors in an oxygen rich environment contain negligible amounts of Co metal and have a large magnetization at room temperature. Structural analysis by X-ray diffraction and magneto-optical measurements indicate that the enhanced magnetism is due, in part, from Zn vacancies that partially compensate the naturally occurring n-type defects. We conclude that strongly magnetic films of Zn0.95Co0.05O that do not contain metallic cobalt can be grown by PLD from Co-metal-precursor targets if the films are grown in an oxygen atmosphere.

  13. Studies on the Surface Morphology and Orientation of CeO2 Films Deposited by Pulsed Laser Ablation

    Science.gov (United States)

    Develos, Katherine; Kusunoki, Masanobu; Ohshima, Shigetoshi

    1998-11-01

    We studied the surface morphology and orientation of CeO2 films grown by pulsed laser ablation (PLA) on r-cut (1\\=102) Al2O3 substrates and evaluated the effects of predeposition annealing conditions of Al2O3 and film thickness of CeO2. The annealing of Al2O3 substrates improves the smoothness of the surface and performing this in high vacuum leads to better crystallinity and orientation of deposited CeO2 films compared to those annealed in oxygen. A critical value of the film thickness was found beyond which the surface roughness increases abruptly. Atomic force microscopy (AFM) study showed that the surface of CeO2 films is characterized by a mazelike pattern. Increasing the film thickness leads to the formation of larger islands which cause the increase in the surface roughness of the films. The areal density and height of these islands increased with film thickness.

  14. Positive magnetoresistance in ferromagnetic Nd-doped In2O3 thin films grown by pulse laser deposition

    KAUST Repository

    Xing, G. Z.

    2014-05-23

    We report the magnetic and magnetotransport properties of (In 0.985Nd0.015)2O2.89 thin films grown by pulse laser deposition. The clear magnetization hysteresis loops with the complementary magnetic domain structure reveal the intrinsic room temperature ferromagnetism in the as-prepared films. The strong sp-f exchange interaction as a result of the rare earth doping is discussed as the origin of the magnetotransport behaviours. A positive magnetoresistance (∼29.2%) was observed at 5 K and ascribed to the strong ferromagnetic sp-f exchange interaction in (In0.985Nd0.015)2O 2.89 thin films due to a large Zeeman splitting in an external magnetic field of 50 KOe. © 2014 AIP Publishing LLC.

  15. Three-dimensional microstructure of high-performance pulsed-laser deposited Ni-YSZ SOFC anodes.

    Science.gov (United States)

    Kennouche, David; Hong, Jongsup; Noh, Ho-Sung; Son, Ji-Won; Barnett, Scott A

    2014-08-07

    The Ni-yttria-stabilized zirconia (YSZ) anode functional layer in solid oxide fuel cells produced by pulsed laser-deposition was studied using three-dimensional tomography. Anode feature sizes of ~130 nm were quite small relative to typical anodes, but errors arising in imaging and segmentation were shown using a sensitivity analysis to be acceptable. Electrochemical characterization showed that these cells achieved a relatively high maximum power density of 1.4 W cm(-2) with low cell resistance at an operating temperature of 600 °C. The tomographic data showed anode three-phase boundary density of ~56 μm(-2), more than 10 times the value observed in conventional Ni-YSZ anodes. Anode polarization resistance values, predicted by combining the structural data and literature values of three-phase boundary resistance in an electrochemical model, were consistent with measured electrochemical impedance spectra, explaining the excellent intermediate-temperature performance of these cells.

  16. Multifractal spectra of scanning electron microscope images of SnO2 thin films prepared by pulsed laser deposition

    Science.gov (United States)

    Chen, Z. W.; Lai, J. K. L.; Shek, C. H.

    2005-09-01

    The concept of fractal geometry has proved useful in describing structures and processes in experimental systems. In this Letter, the surface topographies of SnO2 thin films prepared by pulsed laser deposition for various substrate temperatures were measured by scanning electron microscope (SEM). Multifractal spectra f(α) show that the higher the substrate temperature, the wider the spectrum, and the larger the Δf(Δf=f(α)-f(α)). It is apparent that the nonuniformity of the height distribution increases with the increasing substrate temperature, and the liquid droplets of SnO2 thin films are formed on previous thin films. These results show that the SEM images can be characterized by the multifractal spectra.

  17. Multifractal spectra of scanning electron microscope images of SnO{sub 2} thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.W. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)]. E-mail: cnzwchen@yahoo.com.cn; Lai, J.K.L. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Shek, C.H. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)

    2005-09-26

    The concept of fractal geometry has proved useful in describing structures and processes in experimental systems. In this Letter, the surface topographies of SnO{sub 2} thin films prepared by pulsed laser deposition for various substrate temperatures were measured by scanning electron microscope (SEM). Multifractal spectra f({alpha}) show that the higher the substrate temperature, the wider the spectrum, and the larger the {delta}f({delta}f=f({alpha}{sub min})-f({alpha}{sub max})). It is apparent that the nonuniformity of the height distribution increases with the increasing substrate temperature, and the liquid droplets of SnO{sub 2} thin films are formed on previous thin films. These results show that the SEM images can be characterized by the multifractal spectra.

  18. Properties of La and Nb-modified PZT thin films grown by radio frequency assisted pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Verardi, P. [CNR-Istituto di Acustica, Via del Fosso del Cavaliere 100, I-00133 Rome (Italy); Craciun, F. [CNR-Istituto dei Sistemi Complessi, Via del Fosso del Cavaliere 100, I-00133 Rome (Italy); Dinescu, M. [NILPRP, Bucharest, PO Box MG-16, RO-76900 (Romania)]. E-mail: dinescum@ifin.nipne.ro; Scarisoreanu, N. [NILPRP, Bucharest, PO Box MG-16, RO-76900 (Romania); Moldovan, A. [NILPRP, Bucharest, PO Box MG-16, RO-76900 (Romania); Purice, A. [NILPRP, Bucharest, PO Box MG-16, RO-76900 (Romania); Galassi, C. [CNR-ISTEC, Via Granarolo 64, I 48018 Faenza (Italy)

    2005-04-25

    Lead zirconate titanate ferroelectric thin films added with La and Nb has been grown by radio frequency assisted pulsed laser deposition on Pt/Si, starting from sintered targets. The dielectric properties were measured in a large frequency range and their dependence on the a.c. driving field amplitude has been investigated. A linear decreasing of the dielectric permittivity with frequency logarithm increasing has been evidenced. The most important factor for the driving field amplitude influence on the dielectric properties is the type of vacancies introduced by La and Nb substitutions, which indicates that the dynamics involved in a.c. field behavior is controlled by interaction mechanisms between ferroelectric domain or nanodomain walls and pinning (vacancies) centers.

  19. Photoluminescence and diode characteristic of ZnO thin films/junctions fabricated by pulsed laser deposition (PLD) technique

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Kazuhiro; Komiyama, Takao; Chonan, Yasunori; Yamaguchi, Hiroyuki; Aoyama, Takashi [Department of Electronics and Information Systems, Akita Prefectural University, 84-4 Ebinokuchi, Tsuchiya, Yuri-honjo, Akita 015-0055 (Japan)

    2010-02-15

    ZnO:Ga and ZnO:P films were grown by a pulsed laser deposition (PLD) technique changing the dopant concentrations, and their photoluminescence (PL) spectra were obtained. Then, ZnO:P/ZnO:Ga junctions were fabricated and their junction characteristics were evaluated. As the Ga concentration increased in the films, the PL intensity was decreased while as the P concentration increased, the PL intensity was increased. The maximum PL intensities were obtained for the films of 0.5%(Ga) and 7.0% (P), respectively. Rectifying junction characteristics were observed only for the combination of 0.5-1.0% (Ga) and 5.0% (P) films. Mutual dopant diffusion is supposed to explain the relation between the PL and the junction characteristics. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Facet-dependent photocatalytic performance of NiO oriented thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yali; Zhang, Feng; Wei, Ling [Key Laboratory of Photovoltaic Materials of Henan Province, School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute of Physics for Microsystems, Henan University, Kaifeng 475004 (China); Li, Guoqiang, E-mail: gqli1980@henu.edu.cn [Key Laboratory of Photovoltaic Materials of Henan Province, School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Institute of Physics for Microsystems, Henan University, Kaifeng 475004 (China); Zhang, Weifeng, E-mail: wfzhang@henu.edu.cn [Key Laboratory of Photovoltaic Materials of Henan Province, School of Physics and Electronics, Henan University, Kaifeng 475004 (China)

    2015-01-15

    NiO oriented thin film samples were grown on LaAlO{sub 3} (100), LaAlO{sub 3} (110) and LaAlO{sub 3} (111) substrates by the pulsed laser deposition. The photocatalytic activities of the samples were investigated by degradation of rhodamine B (RhB) under full arc irradiation of a Xe lamp. NiO oriented thin films exhibited difference in photocatalytic oxidization activity. The increasing order of RhB degradation is (100)<(110)<(111), which is consistent with the order of {sup ·}OH generation. The XPS results implied that the ratio of adsorbed oxygen to lattice oxygen was related to the photocatalytic activity.

  1. Pulsed laser deposition and thermoelectric properties of In-and Yb-doped CoSb3 skutterudite thin films

    KAUST Repository

    Sarath Kumar, S. R.

    2011-07-29

    In-and Yb-doped CoSb3 thin films were prepared by pulsed laser deposition. Process optimization studies revealed that a very narrow process window exists for the growth of single-phase skutterudite films. The electrical conductivity and Seebeck coefficient measured in the temperature range 300-700 K revealed an irreversible change on the first heating cycle in argon ambient, which is attributed to the enhanced surface roughness of the films or trace secondary phases. A power factor of 0.68 W m-1 K-1 was obtained at ∼700 K, which is nearly six times lower than that of bulk samples. This difference is attributed to grain boundary scattering that causes a drop in film conductivity. Copyright © Materials Research Society 2011.

  2. Design and development of an ultra-compact drum-shaped chamber for combinatorial pulsed laser deposition

    Science.gov (United States)

    Katayama, M.; Itaka, K.; Matsumoto, Y.; Koinuma, H.

    2006-01-01

    We have designed a compact combinatorial pulsed laser deposition (PLD) chamber as a building block of a desktop laboratory for advanced materials research. Development of small-size systems for the growth and characterization of films would greatly help in interconnecting a variety of analytical tools for rapid screening of advanced materials. This PLD chamber has four special features: (1) a drum-shaped growth chamber, (2) a waterwheel-like combinatorial masking system, (3) a multi-target system having one feedthrough, and (4) a small reflection high-energy electron diffraction (RHEED) system. The performance of this system is demonstrated by the RHEED intensity oscillation during homoepitaxial growth of SrTiO 3 as well as by simultaneous fabrication of a ternary phase diagram of rare earth-doped Y 2O 3 phosphors.

  3. Imaging pulsed laser deposition growth of homo-epitaxial SrTiO3 by low-energy electron microscopy

    Science.gov (United States)

    van der Torren, A. J. H.; van der Molen, S. J.; Aarts, J.

    2016-12-01

    By combining low-energy electron microscopy with in situ pulsed laser deposition we have developed a new technique for film growth analysis, making use of both diffraction and real-space information. Working at the growth temperature, we can use: the intensity and profile variations of the specular beam to follow the coverage in a layer-by-layer fashion; real-space microscopy to follow e.g. atomic steps at the surface; and electron reflectivity to probe the unoccupied band structure of the grown material. Here, we demonstrate our methodology for homo-epitaxial growth of SrTiO3. Interestingly, the same combination of techniques will also be applicable to hetero-epitaxial oxide growth, largely extending the scope of research possibilities.

  4. Studies of growth, microstructure, Raman spectroscopy and annealing effect of pulsed laser deposited Ca-doped NBCO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Palai, R [Department of Physics, University of Strathclyde, Glasgow, G4 0NG (United Kingdom); Romans, E J [Department of Physics, University of Strathclyde, Glasgow, G4 0NG (United Kingdom); Martin, R W [Department of Physics, University of Strathclyde, Glasgow, G4 0NG (United Kingdom); Docherty, F T [Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL (United Kingdom); Maas, P [Department of Physics, University of Strathclyde, Glasgow, G4 0NG (United Kingdom); Pegrum, C M [Department of Physics, University of Strathclyde, Glasgow, G4 0NG (United Kingdom)

    2005-01-07

    Superconducting thin films of Nd{sub 1-x}Ca{sub x}Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} (x = 0.03 and 0.08) have been grown on single crystal SrTiO{sub 3} substrates by pulsed laser deposition. The statistical methods of Experimental Design and regression analysis were used to optimize the film properties and to understand the correlation between the growth parameters and film properties. The orientation of the films was investigated by x-ray diffraction. The surface morphology of the films was examined by atomic force microscopy and scanning tunnelling microscopy. Qualitative and quantitative elemental analyses of the films were carried out using electron probe microanalysis. Micro-Raman spectroscopy was used to study the oxygen sublattice vibrations of the films. The effect of annealing on the superconducting transition temperature of the patterned films was also studied.

  5. Effect of Annealing on the Optical Properties of GaN Films Grown by Pulsed Laser Deposition

    Institute of Scientific and Technical Information of China (English)

    M.Baseer Haider; M.F.Al-Kuhaili; S.M.A.Durrani; Imran Bakhtiari

    2013-01-01

    In the present study,gallium nitride thin films were grown by using pulsed laser deposition.After the growth samples were annealed at 400 and 600 ℃ in the nitrogen atmosphere.Surface morphology of the as-grown and annealed samples was observed by atomic force microscopy.Post-growth annealing results in an improved surface roughness of the films.Chemical analysis of the samples was performed by X-ray photoelectron spectroscopy.Stoichiometric gallium nitride thin films were obtained for the samples annealed at 600 ℃.Optical measurements of the samples were performed to measure the band gap and optical constants of the films.Effect of annealing on the band gap and optical constants of the films was studied.

  6. Structural and magnetic properties of epitaxial delafossite CuFeO{sub 2} thin films grown by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Toyanath; Senty, Tess R.; Trappen, Robbyn; Zhou, Jinling; Borisov, Pavel; Holcomb, Mikel B.; Bristow, Alan D.; Lederman, David [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Chen, Song; Song, Xueyan [Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, West Virginia 26506-6070 (United States); Ferrari, Piero; Cabrera, Alejandro L. [Pontificia Universidad Catolica, Instituto de Física, Santiago (Chile)

    2015-01-07

    Growth of pure phase delafossite CuFeO{sub 2} thin films on Al{sub 2}O{sub 3} (00.1) substrates by pulsed laser deposition was systematically investigated as a function of growth temperature and oxygen pressure. X-ray diffraction, transmission electron microscopy, Raman scattering, and x-ray absorption spectroscopy confirmed the existence of the delafossite phase. Infrared reflectivity spectra determined a band edge at 1.15 eV, in agreement with the bulk delafossite data. Magnetization measurements on CuFeO{sub 2} films demonstrated a phase transition at T{sub C} ≈ 15 ± 1 K, which agrees with the first antiferromagnetic transition at 14 K in the bulk CuFeO{sub 2}. Low temperature magnetic phase is best described by commensurate, weak ferromagnetic spin ordering along the c-axis.

  7. Controlled-Stress Large-Area Pulsed Laser Deposition of Yttria Stabilized Zirconia

    Science.gov (United States)

    2006-05-31

    a wide range of wavelengths from UV to IR. IR Carbon dioxide lasers, near–IR Nd:YAG lasers, HeNe red lasers, argon -ion green lasers, and UV excimer ...lines from argon , krypton, mercury, and xenon lamps . These lamps emitted light at multiple known wavelengths. The spectra from each lamp were

  8. Ultrashort Laser Pulse Phenomena

    CERN Document Server

    Diels, Jean-Claude

    2006-01-01

    Ultrashort Laser Pulse Phenomena, 2e serves as an introduction to the phenomena of ultra short laser pulses and describes how this technology can be used to examine problems in areas such as electromagnetism, optics, and quantum mechanics. Ultrashort Laser Pulse Phenomena combines theoretical backgrounds and experimental techniques and will serve as a manual on designing and constructing femtosecond (""faster than electronics"") systems or experiments from scratch. Beyond the simple optical system, the various sources of ultrashort pulses are presented, again with emphasis on the basic

  9. Structural and functional properties of Al:ZnO thin films grown by Pulsed Laser Deposition at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Gondoni, P.; Ghidelli, M. [Dipartimento di Energia and NEMAS - Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy); Di Fonzo, F. [Center for Nano Science and Technology Polimi, Istituto Italiano di Tecnologia, via Pascoli 70/3, 20133 Milano (Italy); Russo, V. [Dipartimento di Energia and NEMAS - Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy); Bruno, P.; Marti-Rujas, J. [Center for Nano Science and Technology Polimi, Istituto Italiano di Tecnologia, via Pascoli 70/3, 20133 Milano (Italy); Bottani, C.E.; Li Bassi, A. [Dipartimento di Energia and NEMAS - Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy); Center for Nano Science and Technology Polimi, Istituto Italiano di Tecnologia, via Pascoli 70/3, 20133 Milano (Italy); Casari, C.S., E-mail: carlo.casari@polimi.it [Dipartimento di Energia and NEMAS - Center for NanoEngineered Materials and Surfaces, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy); Center for Nano Science and Technology Polimi, Istituto Italiano di Tecnologia, via Pascoli 70/3, 20133 Milano (Italy)

    2012-05-01

    Current research on transparent conductive oxides (TCOs) is focusing on indium-free TCOs, such as Al-doped ZnO (AZO), as an alternative to indium-tin oxide. In this work, AZO thin films were grown by Pulsed Laser Deposition at room temperature in oxygen atmosphere. The O{sub 2} pressure was varied from 0.01 Pa to 10 Pa, highlighting the effects of defect formation and oxygen vacancies on the film properties. Structural properties were characterized by X-ray diffraction and Scanning Electron Microscopy, while functional properties were characterized by measurement of electrical conductivity, Hall mobility, carrier density and optical transmission. At an optimal deposition pressure of 2 Pa, optical transparency in the visible range and minimum resistivity (4.5 Bullet-Operator 10{sup -4} {Omega} cm) were found, comparable to state-of-the-art TCOs. Mean value of visible transparency was shown to increase with increasing pressure, up to 88% at a deposition pressure of 10 Pa.

  10. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Directory of Open Access Journals (Sweden)

    Chih-Ping Yen

    2016-08-01

    Full Text Available The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP, and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE for application to dye-sensitized solar cell (DSSC is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  11. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Science.gov (United States)

    Yen, Chih-Ping; Yu, Pin-Feng; Wang, Jyhpyng; Lin, Jiunn-Yuan; Chen, Yen-Mu; Chen, Szu-yuan

    2016-08-01

    The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP), and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE) for application to dye-sensitized solar cell (DSSC) is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  12. Residual stress and buckling patterns of free-standing yttria-stabilized-zirconia membranes fabricated by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Evans, A.; Prestat, M.; Toelke, R.; Schlupp, M.V.F.; Gauckler, L.J. [ETH Zurich, Nonmetallic Inorganic Materials, Zurich (Switzerland); Safa, Y.; Hocker, T. [ZHAW Winterthur, Institute of Computational Physics, Winterthur (Switzerland); Courbat, J.; Briand, D.; Rooij, N.F. de [Ecole Polytechnique Federale de Lausanne (EPFL), Institute of Microengineering, Neuchatel (Switzerland); Courty, D. [ETH Zurich, Laboratory for Nanometallurgy, Zurich (Switzerland)

    2012-08-15

    The residual stress and buckling patterns of free-standing 8 mol.% yttria-stabilized-zirconia (8YSZ) membranes prepared by pulsed laser deposition and microfabrication techniques on silicon substrates are investigated by wafer curvature, light microscopy, white light interferometry, and nanoindentation. The 300 nm thin 8YSZ membranes (390 {mu}m x 390 {mu}m) deposited at 25 C are almost flat after free-etching, whereas deposition at 700 C yields strongly buckled membranes with a compressive stress of -1,100 {+-} 150 MPa and an out-of-plane-displacement of 6.5 {mu}m. These latter membranes are mechanically stable during thermal cycling up to 500 C. Numerical simulations of the buckling shape using the Rayleigh-Ritz-method and a Young's modulus of 200 GPa are in good agreement with the experimental data. The simulated buckling patterns are used to extract the local stress distribution within the free-standing membrane which consists of tensile and compressive stress regions that are below the failure stresses. This is important regarding the application in, e.g., microsolid oxide fuel cell membranes which must be thermomechanically stable during microfabrication and device operation. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Selective growth of epitaxial Sr2IrO4 by controlling plume dimensions in pulsed laser deposition

    Science.gov (United States)

    Seo, S. S. A.; Nichols, J.; Hwang, J.; Terzic, J.; Gruenewald, J. H.; Souri, M.; Thompson, J.; Connell, J. G.; Cao, G.

    2016-11-01

    We report that epitaxial Sr2IrO4 thin-films can be selectively grown using pulsed laser deposition (PLD). Due to the competition between the Ruddlesden-Popper phases of strontium iridates (Srn+1IrnO3n+1), conventional PLD methods often result in mixed phases of Sr2IrO4 (n = 1), Sr3Ir2O7 (n = 2), and SrIrO3 (n = ∞). We have discovered that reduced PLD plume dimensions and slow deposition rates are the key for stabilizing pure Sr2IrO4 phase thin-films, identified by real-time in-situ monitoring of their optical spectra. The slow film deposition results in a thermodynamically stable TiO2SrO IrO2SrO SrO configuration at an interface rather than TiO2SrO SrO IrO2SrO between a TiO2-terminated SrTiO3 substrate and a Sr2IrO4 thin film, which is consistent with other layered oxides grown by molecular beam epitaxy. Our approach provides an effective method for using PLD to achieve pure phase thin-films of layered materials that are susceptible to several energetically competing phases.

  14. Deposition of organic dyes for dye-sensitized solar cell by using matrix-assisted pulsed laser evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Yen, Chih-Ping [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Yu, Pin-Feng [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China); Wang, Jyhpyng [Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Central University, Taoyuan 320, Taiwan (China); Lin, Jiunn-Yuan [Department of Physics, National Chung Cheng University, Chiayi 621, Taiwan (China); Chen, Yen-Mu [SuperbIN Co., Ltd., Taipei 114, Taiwan (China); Chen, Szu-yuan, E-mail: sychen@ltl.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Department of Physics, National Central University, Taoyuan 320, Taiwan (China)

    2016-08-15

    The deposition of various distinct organic dyes, including ruthenium complex N3, melanin nanoparticle (MNP), and porphyrin-based donor-π-acceptor dye YD2-o-C8, by using matrix-assisted pulsed laser evaporation (MAPLE) for application to dye-sensitized solar cell (DSSC) is investigated systematically. It is found that the two covalently-bonded organic molecules, i.e., MNP and YD2-o-C8, can be transferred from the frozen target to the substrate with maintained molecular integrity. In contrast, N3 disintegrates in the process, presumably due to the lower bonding strength of metal complex compared to covalent bond. With the method, DSSC using YD2-o-C8 is fabricated, and an energy conversion efficiency of 1.47% is attained. The issue of the low penetration depth of dyes deposited by MAPLE and the possible resolution to it are studied. This work demonstrates that MAPLE could be an alternative way for deposition of organic dyes for DSSC.

  15. Structural and electrical properties of different vanadium oxide phases in thin film form synthesized using pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Majid, S. S., E-mail: suhailphy276@gmail.com; Rahman, F. [Department of Physics, Aligarh Muslim University, Aligarh-202002 (India); Shukla, D. K.; Choudhary, R. J.; Phase, D. M. [UGC-DAE Consortium for Scientific Research, Indore-452001 (India)

    2015-06-24

    We present here the structural and electrical properties of the thin films of V{sub 2}O{sub 3} (Vanadium sesquioxide) and V{sub 5}O{sub 9}. Both these oxide phases, V{sub 2}O{sub 3} and V{sub 5}O{sub 9}, have beenachieved on (001) orientedSi substrate using the V{sub 2}O{sub 5} target by optimizing the deposition parameters using pulsed laser deposition technique (PLD).Deposited films were characterized by X-ray diffraction(XRD)and four probe temperature dependent resistivity measurements. XRD studies reveal the V{sub 2}O{sub 3} and V{sub 5}O{sub 9} phases and the amount of strain present in both these films. The temperature dependency of electrical resistivity confirmed the characteristic metal-insulator transitions (MIT) for both the films, V{sub 2}O{sub 3} and V{sub 5}O{sub 9}.

  16. Thermal stability and thermal expansion behaviour of ZrO{sub 2}/Y{sub 2}O{sub 3} multilayers deposited by pulsed laser deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Maneesha, E-mail: pkigcar@gmail.com [Materials Synthesis and Structural Characterisation Division, Physical Metallurgy Group, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Kuppusami, P. [Centre for Nanoscience and Nanotechnology, Sathyabama University, Chennai, 600119 Tamil Nadu (India); Murugesan, S.; Ghosh, Chanchal; Divakar, R.; Singh, Akash; Mohandas, E. [Materials Synthesis and Structural Characterisation Division, Physical Metallurgy Group, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

    2015-07-15

    Multilayers of ZrO{sub 2}/Y{sub 2}O{sub 3} were prepared by pulsed laser deposition technique with variation in the ZrO{sub 2} layer thickness from 5 to 30 nm keeping the Y{sub 2}O{sub 3} layer thickness constant (∼10 nm). The stability, phase evolution and thermal expansion behaviour of the multilayers were analyzed by high temperature x-ray diffraction technique, in the temperature range of 300–1373 K. Unlike the single layer of ZrO{sub 2} film, which shows a mixture of tetragonal and monoclinic phase, the ZrO{sub 2} layers in multilayers show tetragonal phase in case of all the multilayers investigated in the present work. The values of coefficient of thermal expansion (CTE) decrease with increase in the ZrO{sub 2} layer thickness. The CTE of both ZrO{sub 2} and Y{sub 2}O{sub 3} are found to be influenced by their mutual solubility as well as due to interdiffusion of these oxides taking place along the interfaces of the multilayers, especially during high temperature heat-treatment. - Highlights: • ZrO{sub 2}/Y{sub 2}O{sub 3} multilayers were deposited by pulsed laser deposition technique. • Formation of tetragonal phase of ZrO{sub 2} and cubic phase of Y{sub 2}O{sub 3} were observed. • The multilayers films show good thermal stability upto temperature 1373 K. • The coefficient of thermal expansion (CTE) of t-ZrO{sub 2} decreases with increase in ZrO{sub 2} layer thickness.

  17. Pulsed laser deposited amorphous chalcogenide and alumino-silicate thin films and their multilayered structures for photonic applications

    Energy Technology Data Exchange (ETDEWEB)

    Němec, P. [Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic); Charrier, J. [FOTON, UMR CNRS 6082, Enssat, 6 rue de Kerampont, BP 80518, 22305 Lannion (France); Cathelinaud, M. [Missions des Ressources et Compétences Technologiques, UPS CNRS 2274, 92195 Meudon (France); Allix, M. [CEMHTI-CNRS, Site Haute Température, Orléans (France); Adam, J.-L.; Zhang, S. [Equipe Verres et Céramiques, UMR-CNRS 6226, Sciences Chimiques de Rennes (SCR), Université de Rennes 1, 35042 Rennes Cedex (France); Nazabal, V., E-mail: virginie.nazabal@univ-rennes1.fr [Department of Graphic Arts and Photophysics, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 53210 Pardubice (Czech Republic); Equipe Verres et Céramiques, UMR-CNRS 6226, Sciences Chimiques de Rennes (SCR), Université de Rennes 1, 35042 Rennes Cedex (France)

    2013-07-31

    Amorphous chalcogenide and alumino-silicate thin films were fabricated by the pulsed laser deposition technique. Prepared films were characterized in terms of their morphology, chemical composition, and optical properties. Multilayered thin film stacks for reflectors and vertical microcavities were designed for telecommunication wavelength and the window of atmosphere transparency (band II) at 1.54 μm and 4.65 μm, respectively. Bearing in mind the benefit coming from the opportunity of an efficient wavelength tuning or, conversely, to stabilize the photoinduced effects in chalcogenide films as well as to improve their mechanical properties and/or their chemical durability, several pairs of materials from pure chalcogenide layers to chalcogenide/oxide layers were investigated. Different layer stacks were fabricated in order to check the compatibility between dissimilar materials which can have a strong influence on the interface roughness, adhesion, density, and homogeneity, for instance. Three different reflector designs were formulated and tested including all-chalcogenide layers (As{sub 40}Se{sub 60}/Ge{sub 25}Sb{sub 5}S{sub 70}) and mixed chalcogenide-oxide layers (As{sub 40}Se{sub 60}/alumino-silicate and Ga{sub 10}Ge{sub 15}Te{sub 75}/alumino-silicate). Prepared multilayers showed good compatibility between different material pairs deposited by laser ablation despite the diversity of chemical compositions. As{sub 40}Se{sub 60}/alumino-silicate reflector showed the best parameters; its stop band (R > 97% at 8° off-normal incidence) has a bandwidth of ∼ 100 nm and it is centered at 1490 nm. The quality of the different mirrors developed was good enough to try to obtain a microcavity structure for the 1.5 μm telecommunication wavelength made of chalcogenide layers. The microcavity structure consists of Ga{sub 5}Ge{sub 20}Sb{sub 10}S{sub 65} (doped with 5000 ppm of Er{sup 3+}) spacer surrounded by two 10-layer As{sub 40}Se{sub 60}/Ge{sub 25}Sb{sub 5}S{sub 70

  18. Factors controlling the microstructure of Ce0.9Gd0.1O2-δ films in pulsed laser deposition process

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Heiroth, S.; Döbeli, M.;

    Films of Ce0.9Gd0.1O2-δ(CGO10) are prepared at a range of conditions by pulsed laser deposition (PLD) on a single crystal Si (100) and MgO (100), and on a polycrystalline Pt/MgO (100) substrate. The relationship between the film microstructure, crystallography, chemical composition and PLD...

  19. Ordered Arrays of Ferroelectric Nanoparticles by Pulsed Laser Deposition on PS-b-P4VP(PDP) Supramolecule-Based Templates

    NARCIS (Netherlands)

    van Zoelen, Wendy; Vlooswijk, Ard H. G.; Ferri, Anthony; Andringa, Anne-Marije; Noheda, Beatriz; ten Brinke, Gerrit

    2009-01-01

    Thin films of comb-shaped supramolecules have been used to create arrays of spatially separated ordered nanorods with a polystyrene core and a poly(4-vinyl pyridine) corona. Room temperature pulsed laser deposition of a uniform layer of lead titanate on top of these nanorod arrays and Subsequent hea

  20. Epitaxy of Fe3O4 on Si(001) by pulsed laser deposition using a TiN/MgO buffer layer

    OpenAIRE

    Reisinger, D; Schonecke, M.; Brenninger, T.; Opel, M.; Erb, A.; Alff, L.; Gross, R.

    2003-01-01

    Epitaxy of oxide materials on silicon (Si) substrates is of great interest for future functional devices using the large variety of physical properties of the oxides as ferroelectricity, ferromagnetism, or superconductivity. Recently, materials with high spin polarization of the charge carriers have become interesting for semiconductor-oxide hybrid devices in spin electronics. Here, we report on pulsed laser deposition of magnetite (Fe3O4) on Si(001) substrates cleaned by an in situ laser bea...

  1. Excimer Laser Pulse Compress With Pulse Feedback

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>To attain a shorter laser pulse, a compressing technique called pulse feedback was developed from the saturation gain switch applied to the amplification in a discharge pumping excimer laser cavity. It can

  2. CdTe:Ge/Si (100) thin films grown by pulsed laser deposition (PLD) for photonic devices

    Science.gov (United States)

    Neretina, S.; Hughes, R. A.; Preston, J. S.; Sochinskii, N. V.; Mascher, P.

    2005-09-01

    Cadmium Telluride (CdTe) is a well known photonic material in the fields of infrared imaging and solar cells. Its nonlinear optical properties also make it a promising candidate for novel telecom applications that would utilize its high Kerr coefficient to produce advanced logical devices such as switches, routers and wavelength converters. The large photorefractive effect observed in CdTe also makes possible high-speed devices suitable for optical data processing. In order to advance such photorefractive waveguide applications, we have deposited CdTe films on silicon substrates with a native oxide layer using the pulsed laser deposition technique (PLD). Silicon was chosen as the substrate material as it is suitable for the monolithic integration of logical devices. Maintaining an oxide layer was deemed necessary as a high refractive index mismatch is desirable for high-index contrast waveguide based applications and such an index mismatch could be provided by a reasonably thick layer of SiO2. Films exhibiting some structural deficiencies, but with high optical quality were deposited through the optimization of the growth parameters. X-ray diffraction data indicates that the films are [111] oriented with rocking curves of substantial width. Atomic force microscopy images confirm that the films have a smooth surface morphology as was suggested by their mirror-like appearance. Using the optimum growth conditions, CdTe films doped with germanium were also deposited as this dopant introduces deep donor levels that enhance the photorefractive effect. A comparison of the optical properties obtained from the doped and undoped films indicate that impurities can have a marked effect on the index of refraction and extinction coefficient. Such alterations to the optical constants must be considered in the design of waveguide structures.

  3. Optical parameters of In Se and In Se Te thin amorphous films prepared by pulsed laser deposition

    Science.gov (United States)

    Hrdlicka, M.; Prikryl, J.; Pavlista, M.; Benes, L.; Vlcek, M.; Frumar, M.

    2007-05-01

    The thin films of materials based on In Se are under study for their applicability in photovoltaic devices, solid-state batteries and phase-change memories. The amorphous thin films of In2Se3-xTex (x=0 1.5) and InSe were prepared by pulsed laser deposition method (PLD) using a KrF excimer laser beam (λ=248 nm, 0.5 J cm-2) from polycrystalline bulk targets. The compositions of films verified by energy-dispersive X-ray analysis (EDX) were close to the compositions of targets. The surfaces of PLD films containing small amount of droplets were viewed by optical and scanning electron microscopy (SEM). The optical properties (transmittance and reflectance spectra, spectral dependence of index of refraction, optical gap, single-oscillator energy, dispersion energy, dielectric constant) of the films were determined. The values of index of refraction increased with increasing substitution of Te for Se in In2Se3 films, the values of the optical gap decreased with increasing substitution of Te for Se in In2Se3 films.

  4. Effect of Ablation Rate on the Microstructure and Electrochromic Properties of Pulsed-Laser-Deposited Molybdenum Oxide Thin Films.

    Science.gov (United States)

    Santhosh, S; Mathankumar, M; Selva Chandrasekaran, S; Nanda Kumar, A K; Murugan, P; Subramanian, B

    2017-01-10

    Molybdenum trioxide (MoO3) is a well-known electrochromic material. In the present work, n-type α-MoO3 thin films with both direct and indirect band gaps were fabricated by varying the laser repetition (ablation) rate in a pulsed laser deposition (PLD) system at a constant reactive O2 pressure. The electrochromic properties of the films are compared and correlated to the microstructure and molecular-level coordination. Mixed amorphous and textured crystallites evolve at the microstructural level. At the molecular level, using NMR and EPR, we show that the change in the repetition rate results in a variation of the molybdenum coordination with oxygen: at low repetition rates (2 Hz), the larger the octahedral coordination, and greater the texture, whereas at 10 Hz, tetrahedral coordination is significant. The anion vacancies also introduce a large density of defect states into the band gap, as evidenced by XPS studies of the valence band and supported by DFT calculations. The electrochromic contrast improved remarkably by almost 100% at higher repetition rates whereas the switching speed decreased by almost 6-fold. Although the electrochromic contrast and coloration efficiency were better at higher repetition rates, the switching speed, reversibility, and stability were better at low repetition rates. This difference in the electrochromic properties of the two MoO3 films is attributed to the variation in the defect and molecular coordination states of the Mo cation.

  5. Nanostructured europium oxide thin films deposited by pulsed laser ablation of a metallic target in a He buffer atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Luna, H.; Franceschini, D. F.; Prioli, R.; Guimaraes, R. B.; Sanchez, C. M.; Canal, G. P.; Barbosa, M. D. L.; Galvao, R. M. O. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Cx. Postal 68528, Rio de Janeiro, RJ 21941-972 (Brazil); Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ 24210-346 (Brazil); Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, 22453-970, Rio de Janeiro, RJ (Brazil); Instituto de Fisica, Universidade Federal Fluminense, Niteroi, RJ 24210-346 (Brazil); Centro Brasileiro de Pesquisas Fisicas, Laboratorio de Plasmas Aplicados, Rua Xavier Sigaud 150, 22290-180, Rio de Janeiro, RJ (Brazil); Instituto de Fisica, Departamento de Fisica Nuclear, Universidade de Sao Paulo, Caixa Postal 66328, 05315-970, Sao Paulo, SP (Brazil); Centro Brasileiro de Pesquisas Fisicas, Laboratorio de Plasmas Aplicados, Rua Xavier Sigaud 150, 22290-180, Rio de Janeiro, RJ (Brazil)

    2010-09-15

    Nanostrucured europium oxide and hydroxide films were obtained by pulsed Nd:YAG (532 nm) laser ablation of a europium metallic target, in the presence of a 1 mbar helium buffer atmosphere. Both the produced film and the ambient plasma were characterized. The plasma was monitored by an electrostatic probe, for plume expansion in vacuum or in the presence of the buffer atmosphere. The time evolution of the ion saturation current was obtained for several probe to substrate distances. The results show the splitting of the plume into two velocity groups, being the lower velocity profile associated with metal cluster formation within the plume. The films were obtained in the presence of helium atmosphere, for several target-to-substrate distances. They were analyzed by Rutherford backscattering spectrometry, x-ray diffraction, and atomic force microscopy, for as-deposited and 600 deg. C treated-in-air samples. The results show that the as-deposited samples are amorphous and have chemical composition compatible with europium hydroxide. The thermally treated samples show x-ray diffraction peaks of Eu{sub 2}O{sub 3}, with chemical composition showing excess oxygen. Film nanostructuring was shown to be strongly correlated with cluster formation, as shown by velocity splitting in probe current versus time plots.

  6. Microstructural, nanomechanical, and microtribological properties of Pb thin films prepared by pulsed laser deposition and thermal evaporation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Broitman, Esteban, E-mail: esbro@ifm.liu.se [Thin Film Physics Division, IFM, Linköping University, SE-581 83 Linköping (Sweden); Flores-Ruiz, Francisco J. [Thin Film Physics Division, IFM, Linköping University, SE-581 83 Linköping, Sweden and Centro de Investigación y de Estudios Avanzados del I.P.N., Unidad Querétaro, Querétaro 76230 (Mexico); Di Giulio, Massimo [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce (Italy); Gontad, Francisco; Lorusso, Antonella; Perrone, Alessio [Università del Salento, Dipartimento di Matematica e Fisica “E. De Giorgi”, 73100 Lecce, Italy and INFN-Istituto Nazionale di Fisica Nucleare, 73100 Lecce (Italy)

    2016-03-15

    In this work, the authors compare the morphological, structural, nanomechanical, and microtribological properties of Pb films deposited by thermal evaporation (TE) and pulsed laser deposition (PLD) techniques onto Si (111) substrates. Films were investigated by scanning electron microscopy, surface probe microscopy, and x-ray diffraction in θ-2θ geometry to determine their morphology, root-mean-square (RMS) roughness, and microstructure, respectively. TE films showed a percolated morphology with densely packed fibrous grains while PLD films had a granular morphology with a columnar and tightly packed structure in accordance with the zone growth model of Thornton. Moreover, PLD films presented a more polycrystalline structure with respect to TE films, with RMS roughness of 14 and 10 nm, respectively. Hardness and elastic modulus vary from 2.1 to 0.8 GPa and from 14 to 10 GPa for PLD and TE films, respectively. A reciprocal friction test has shown that PLD films have lower friction coefficient and wear rate than TE films. Our study has demonstrated for first time that, at the microscale, Pb films do not show the same simple lubricious properties measured at the macroscale.

  7. Electronic transport in highly conducting Si-doped ZnO thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Vladimir L.; Vai, Alex T.; Edwards, Peter P., E-mail: peter.edwards@chem.ox.ac.uk [Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, Oxford OX1 3QR (United Kingdom); Al-Mamouri, Malek; Stuart Abell, J. [Department of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT (United Kingdom); Pepper, Michael [Department of Electronic and Electrical Engineering, University College London, London WC1E 7JE (United Kingdom)

    2015-12-07

    Highly conducting (ρ = 3.9 × 10{sup −4} Ωcm) and transparent (83%) polycrystalline Si-doped ZnO (SiZO) thin films have been deposited onto borosilicate glass substrates by pulsed laser deposition from (ZnO){sub 1−x}(SiO{sub 2}){sub x} (0 ≤ x ≤ 0.05) ceramic targets prepared using a sol-gel technique. Along with their structural, chemical, and optical properties, the electronic transport within these SiZO samples has been investigated as a function of silicon doping level and temperature. Measurements made between 80 and 350 K reveal an almost temperature-independent carrier concentration consistent with degenerate metallic conduction in all of these samples. The temperature-dependent Hall mobility has been modeled by considering the varying contribution of grain boundary and electron-phonon scattering in samples with different nominal silicon concentrations.

  8. Low temperature epitaxy of Ge-Sb-Te films on BaF{sub 2} (111) by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Thelander, E., E-mail: erik.thelander@iom-leipzig.de; Gerlach, J. W.; Ross, U.; Lotnyk, A.; Rauschenbach, B. [Leibniz-Institut für Oberflächenmodifizierung e.V., Leipzig 04318 (Germany)

    2014-12-01

    Pulsed laser deposition was employed to deposit epitaxial Ge{sub 2}Sb{sub 2}Te{sub 5}-layers on the (111) plane of BaF{sub 2} single crystal substrates. X-ray diffraction measurements show a process temperature window for epitaxial growth between 85 °C and 295 °C. No crystalline growth is observed for lower temperatures, whereas higher temperatures lead to strong desorption of the film constituents. The films are of hexagonal structure with lattice parameters consistent with existing models. X-ray pole figure measurements reveal that the films grow with one single out-of-plane crystal orientation, but rotational twin domains are present. The out-of-plane epitaxial relationship is determined to be Ge{sub 2}Sb{sub 2}Te{sub 5}(0001) || BaF{sub 2}(111), whereas the in-plane relationship is characterized by two directions, i.e., Ge{sub 2}Sb{sub 2}Te{sub 5} [-12-10] || BaF{sub 2}[1-10] and Ge{sub 2}Sb{sub 2}Te{sub 5}[1-210] || BaF{sub 2}[1-10]. Aberration-corrected high-resolution scanning transmission electron microscopy was used to resolve the local atomic structure and confirm the hexagonal structure of the films.

  9. Nucleation mechanism and microstructural assessment of SnO{sub 2} nanowires prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.W. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)]. E-mail: cnzwchen@yahoo.com.cn; Lai, J.K.L. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Shek, C.H. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong (China)

    2005-10-03

    Tin dioxide, SnO{sub 2}, nanowires have been successfully synthesized by a pulsed laser deposition process based on a sintered cassiterite SnO{sub 2} target, being deposited on Si (100) substrates at room temperature. Transmission electron microscopy shows that nanowires are structurally perfect and uniform, and diameters range from 10 nm to 30 nm, and lengths of several hundreds nanometers to a few micrometers. X-ray diffraction and energy dispersive X-ray spectroscopy analysis indicate that the nanowires have the same crystal structure and chemical composition found in the tetragonal rutile form of SnO{sub 2}. Selected area electron diffraction and high-resolution transmission electron microscopy reveal that the nanowires grow along the [110] growth direction. In addition to the fundamental Raman scattering peaks, the other two Raman scattering peaks are also observed. We discussed the possible reasons for the appearance of Raman scattering peaks at 518.7 and 701.8 cm{sup -1}. The growth process of the SnO{sub 2} nanowires is suggested to follow a vapor-solid mechanism.

  10. Properties of ZnO thin films grown on Si substrates in vacuum and oxygen ambient by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Jie [State Key Laboratory for Materials Modification by Laser, Ion, Electron Beams, Department of Physics, Dalian University of Technology, Dalian 116024 (China) and Department of Physics, Kunming University of Science and Technology, Kunming 650093 (China)]. E-mail: jiezhao_sub@163.com; Hu Lizhong [State Key Laboratory for Materials Modification by Laser, Ion, Electron Beams, Department of Physics, Dalian University of Technology, Dalian 116024 (China); Liu Weifeng [State Key Laboratory for Materials Modification by Laser, Ion, Electron Beams, Department of Physics, Dalian University of Technology, Dalian 116024 (China); Wang Zhaoyang [State Key Laboratory for Materials Modification by Laser, Ion, Electron Beams, Department of Physics, Dalian University of Technology, Dalian 116024 (China)

    2007-05-15

    Epitaxial ZnO thin films have been synthesized directly on Si(1 1 1) substrates by pulsed laser deposition (PLD) in vacuum. The reflection high-energy electron diffraction (RHEED) indicates that streaky patterns can be clearly observed from the ZnO epilayers prepared at 600 and 650 deg. C, revealing a two-dimensional (2D) growth mode. While the ZnO thin film deposited in oxygen ambient shows ring RHEED pattern. There is a compressive in-plane stress existing in the ZnO epitaxial film, but a tensile one in the polycrystalline film. Compared with the ZnO epilayer, the ZnO polycrystalline film shows more intense ultraviolet emission (UVE) with a small full width at half maximum (FWHM) of 89 meV. It is suggested that the atomically flat epilayers may be powerfully used as transitive stratums to grow high-quality ZnO films suitable for the fabrication of optoelectronic devices.

  11. Pulsed laser deposition of HfO2 thin films on indium zinc oxide: Band offsets measurements

    Science.gov (United States)

    Craciun, D.; Craciun, V.

    2017-04-01

    One of the most used dielectric films for amorphous indium zinc oxide (IZO) based thin films transistor is HfO2. The estimation of the valence band discontinuity (ΔEV) of HfO2/IZO heterostructure grown using the pulsed laser deposition technique, with In/(In + Zn) = 0.79, was obtained from X-ray photoelectron spectroscopy (XPS) measurements. The binding energies of Hf 4d5, Zn 2p3 and In 3d5 core levels and valence band maxima were measured for thick pure films and for a very thin HfO2 film deposited on a thick IZO film. A value of ΔEV = 1.75 ± 0.05 eV was estimated for the heterostructure. Taking into account the measured HfO2 and IZO optical bandgap values of 5.50 eV and 3.10 eV, respectively, a conduction band offset ΔEC = 0.65 ± 0.05 eV in HfO2/IZO heterostructure was then obtained.

  12. Ferroelectric BaTiO3 thin films on Ti substrate fabricated using pulsed-laser deposition.

    Science.gov (United States)

    He, J; Jiang, J C; Liu, J; Collins, G; Chen, C L; Lin, B; Giurgiutiu, V; Guo, R Y; Bhalla, A; Meletis, E I

    2010-09-01

    We report on the fabrication of ferroelectric BaTiO3 thin films on titanium substrates using pulsed laser deposition and their microstructures and properties. Electron microscopy studies reveal that BaTiO3 films are composed of crystalline assemblage of nanopillars with average cross sections from 100 nm to 200 nm. The BaTiO3 films have good interface structures and strong adhesion with respect to Ti substrates by forming a rutile TiO2 intermediate layer with a gradient microstructure. The room temperature ferroelectric polarization measurements show that the as-deposited BTO films possess nearly the same spontaneous polarization as the bulk BTO ceramics indicating formation of ferroelectric domains in the films. Successful fabrication of such ferroelectric films on Ti has significant importance for the development of new applications such as structural health monitoring spanning from aerospace to civil infrastructure. The work can be extended to integrate other ferroelectric oxide films with various promising properties to monitor the structural health of materials.

  13. Spectroscopic characterization of the plasmas formed during the deposition of ZnO and Al-doped ZnO films by plasma-assisted pulsed laser deposition

    Science.gov (United States)

    Liang, Peipei; Cai, Hua; Yang, Xu; Li, Hui; Zhang, Wu; Xu, Ning; Sun, Jian; Wu, Jiada

    2016-11-01

    An oxygen-zinc plasma and an oxygen-zinc-aluminum plasma are formed by pulsed laser ablation of a Zn target or pulsed laser co-ablation of a Zn target and an Al target in an electron cyclotron resonance (ECR) discharge-generated oxygen plasma for the deposition of ZnO and Al-doped ZnO (AZO) films. The plasmas are characterized spectroscopically by time-integrated and time-resolved optical emission spectroscopy. Both the oxygen-zinc plasma and the oxygen-zinc-aluminum plasma contain excited species originally present in the working O2 gas and energetic species ablated from the targets. The optical emission of the oxygen-zinc-aluminum plasma is abundant in the emission bands of oxygen molecular ions and the emission lines of mono-atomic oxygen, zinc and aluminum atoms and atomic ions. The time-integrated spectra as well as the time-resolved spectra of the plasma emission indicate that the oxygen species in the ECR oxygen plasma experience additional excitation by the expanding ablation plumes, and the ablated species are excited frequently when traveling accompanying the plume expansion in the oxygen plasma, making the formed plasma highly excited and very reactive, which plays an important role in the reactive growth of ZnO matrix and the in-situ doping of Al into the growing ZnO matrix. The deposited ZnO and AZO films were evaluated for composition analysis by energy dispersive X-ray spectroscopy, structure characterization by X-ray diffraction and optical transmission measurement. The deposited ZnO is slightly rich in O. The Al concentration of the AZO films can be controlled and varied simply by changing the repetition rate of the laser used for Al target ablation. Both the ZnO and the AZO films are featured with hexagonal wurtzite crystal structure and exhibit high optical transparency in a wide spectral region. Al doping results in an improvement in the ultraviolet transparency, a blue shift in the absorption edge and a widening of the band gap.

  14. Pulsed laser deposition of multiwall carbon nanotube/NiO nanocomposite thin films

    CSIR Research Space (South Africa)

    Yalisi, B

    2011-07-01

    Full Text Available EM TT PD CRO Nd:YAG ? Nd:YAG Laser laser BS - Beam splitter (R=93%, T=4%) M1- Mirror BP - Beam profiler/Camera CRO - Oscilloscope EM - Energy meter PD ? Photo detector TT-Target testing set up Target PLD Chamber PLD Experimental set up...

  15. Growth and microstructure of columnar Y-doped SrZrO{sub 3} films deposited on Pt-coated MgO by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Sijun, E-mail: sluo1@tulane.edu; Riggs, Brian C.; Shipman, Joshua T.; Adireddy, Shiva; Sklare, Samuel C.; Chrisey, Douglas B., E-mail: dchrisey@tulane.edu [Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118 (United States); Zhang, Xiaodong; Koplitz, Brent [Department of Chemistry, Tulane University, New Orleans, Louisiana 70118 (United States)

    2015-07-21

    Direct integration of proton conductor films on Pt-coated substrates opens the way to film-based proton transport devices. Columnar SrZr{sub 0.95}Y{sub 0.05}O{sub 3−δ} (SZY) films with dense microstructure were deposited on Pt-coated MgO(100) substrates at 830 °C by pulsed laser deposition. The optimal window of ambient O{sub 2} pressure for good crystallinity of SZY films is from 400 to 600 mTorr. The ambient O{sub 2} compresses the plasma plume of SZY and increases the deposition rate. The 10 nm thick Ti adhesion layer on MgO(100) greatly affects the orientation of the sputtered Pt layers. Pt deposited directly on MgO shows a highly (111)-preferred orientation and leads to preferentially oriented SZY films while the addition of a Ti adhesion layer makes Pt show a less preferential orientation that leads to randomly oriented SZY films. The RMS surface roughness of preferentially oriented SZY films is larger than that of randomly oriented SZY films deposited under the same ambient O{sub 2} pressure. As the O{sub 2} pressure increased, the RMS surface roughness of preferentially oriented SZY films increased, reaching 45.7 nm (2.61% of film thickness) at 600 mTorr. This study revealed the ambient O{sub 2} pressure and orientation dependent surface roughness of SZY films grown on Pt-coated MgO substrates, which provides the potential to control the surface microstructure of SZY films for electrochemical applications in film-based hydrogen devices.

  16. Effect of boron incorporation on the structure and electrical properties of diamond-like carbon films deposited by femtosecond and nanosecond pulsed laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, A. [Laboratoire Hubert Curien, UMR 5516 CNRS, Universite Jean Monnet, 18 Rue Pr. Benoit Lauras, 42000 Saint-Etienne (France); Bourgeois, O. [Institut Neel, UPR 2940 CNRS, 25 Avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Sanchez-Lopez, J.C. [Instituto de Ciencia de Materiales de Sevilla, Avda. Americo Vespucio, 49 41092 Sevilla (Spain); Rouzaud, J.-N. [Laboratoire de Geologie, UMR 8538 CNRS, Ecole Normale Superieure, 45 Rue d' Ulm, 75230 Paris Cedex 05 (France); Rojas, T.C. [Instituto de Ciencia de Materiales de Sevilla, Avda. Americo Vespucio, 49 41092 Sevilla (Spain); Loir, A.-S. [Laboratoire Hubert Curien, UMR 5516 CNRS, Universite Jean Monnet, 18 Rue Pr. Benoit Lauras, 42000 Saint-Etienne (France); Garden, J.-L. [Institut Neel, UPR 2940 CNRS, 25 Avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Garrelie, F. [Laboratoire Hubert Curien, UMR 5516 CNRS, Universite Jean Monnet, 18 Rue Pr. Benoit Lauras, 42000 Saint-Etienne (France); Donnet, C., E-mail: christophe.donnet@univ-st-etienne.f [Laboratoire Hubert Curien, UMR 5516 CNRS, Universite Jean Monnet, 18 Rue Pr. Benoit Lauras, 42000 Saint-Etienne (France)

    2009-12-31

    The influence of the incorporation of boron in diamond-like carbon (DLC) films on the microstructure of the coatings has been investigated. The boron-containing DLC films (a-C:B) have been deposited by pulsed laser deposition (PLD) at room temperature in high vacuum conditions, by ablating graphite and boron targets either with a femtosecond pulsed laser (800 nm, 150 fs, fs-DLC) or with a nanosecond pulsed laser (248 nm, 20 ns, ns-DLC). Alternative ablation of the graphite and boron targets has been carried out to deposit the a-C:B films. The film structure and composition have been highlighted by coupling Field Emission Scanning Electron Microscopy, Electron Energy Loss Spectroscopy and High Resolution Transmission Electron Microscopy. Using the B K-edge, EELS characterization reveals the boron effect on the carbon bonding. Moreover, the plasmon energy reveals a tendency of graphitization associated to the boron doping. Pure boron particles have been characterized by HRTEM and reveal that those particles are amorphous or crystallized. The nanostructures of the boron-doped ns-DLC and the boron-doped fs-DLC are thus compared. In particular, the incorporation of boron in the DLC matrix is highlighted, depending on the laser used for deposition. Electrical measurements show that some of these films have potentialities to be used in low temperature thermometry, considering their conductivity and temperature coefficient of resistance (TCR) estimated within the temperature range 160-300 K.

  17. Fabrication of solid-state thin-film batteries using LiMnPO{sub 4} thin films deposited by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Daichi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan); Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Kuwata, Naoaki, E-mail: kuwata@tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan); Matsuda, Yasutaka; Kawamura, Junichi [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan); Kang, Feiyu [Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2015-03-31

    Solid-state thin-film batteries using LiMnPO{sub 4} thin films as positive electrodes were fabricated and the electrochemical properties were characterized. The LiMnPO{sub 4} thin films were deposited on Pt coated glass substrates by pulsed laser deposition. In-plane X-ray diffraction revealed that the LiMnPO{sub 4} thin films were well crystallized and may have a texture with a (020) orientation. The deposition conditions were optimized; the substrate temperature was 600 °C and the argon pressure was 100 Pa. The electrochemical measurements indicate that the LiMnPO{sub 4} films show charge and discharge peaks at 4.3 V and 4.1 V, respectively. The electrical conductivity of the LiMnPO{sub 4} film was measured by impedance spectroscopy to be 2 × 10{sup −11} S cm{sup −1} at room temperature. The solid-state thin-film batteries that show excellent cycle stability were fabricated using the LiMnPO{sub 4} thin film. Moreover, the chemical diffusion of the LiMnPO{sub 4} thin film was studied by cyclic voltammetry. The chemical diffusion coefficient of the LiMnPO{sub 4} thin film is estimated to be 3.0 × 10{sup −17} cm{sup 2} s{sup −1}, which is approximately four orders magnitude smaller than the LiFePO{sub 4} thin films, and the capacity of the thin-film battery was gradually increased for 500 cycles. - Highlights: • Olivine-type LiMnPO{sub 4} thin-films were fabricated by pulsed laser deposition. • The electrochemical properties were characterized by using solid-state thin-film batteries. • Chemical diffusion coefficient of LiMnPO{sub 4} thin film was estimated by cyclic voltammetry. • Thin-film batteries, Li/Li{sub 3}PO{sub 4}/LiMnPO{sub 4}, show excellent cycle stability up to 500 cycles.

  18. Factors controlling the microstructure of Ce0.9Gd0.1O2-δ films in pulsed laser deposition process

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Heiroth, S.; Döbeli, M.;

    2010-01-01

    Films of Ce0.9Gd0.1O2-delta (CGO10) are prepared at a range of conditions by pulsed laser deposition (PLD) on a single crystal Si (100) and MgO (100), and on a polycrystalline Pt/MgO (100) substrate. The relationship between the film microstructure, crystallography, chemical composition and PLD...... processing parameters is studied. It is found that the laser fluence has no significant impact on the film density, whereas the substrate temperature and the oxygen pressure are of essential importance for the film microstructure development. The reduction of deposition temperature, down to 250 oC, together...

  19. Epitaxial growth of magnetic ZnCuO thin films by pulsed laser deposition

    Science.gov (United States)

    Kim, Dong Hun; Kim, Tae Cheol; Lee, Seung Han; Jung, Hyun Kyu; Jeong, Jaeeun; Han, Seung Ho

    2017-02-01

    The crystal structure and magnetic properties of epitaxial ZnO thin films doped with 5 at% Cu on SrTiO3 (001) and (111) substrates were investigated. In the case of films deposited in oxygen, unique crystallographic growth directions on different substrates were observed, while a metallic phase was detected in films grown under vacuum. The Cu-doped ZnO thin films deposited on the SrTiO3 (111) substrates, with hexagonal structures, showed a single epitaxial relationship with the substrates, whereas those deposited on the SrTiO3 (001) substrates showed a double epitaxial growth mode. The epitaxial ZnCuO thin films deposited on the SrTiO3 (111) substrates under high vacuum exhibited a ferromagnetic signal at room temperature.

  20. Nanomechanical and electrical properties of Nb thin films deposited on Pb substrates by pulsed laser deposition as a new concept photocathode for superconductor cavities

    Science.gov (United States)

    Gontad, F.; Lorusso, A.; Panareo, M.; Monteduro, A. G.; Maruccio, G.; Broitman, E.; Perrone, A.

    2015-12-01

    We report a design of photocathode, which combines the good photoemissive properties of lead (Pb) and the advantages of superconducting performance of niobium (Nb) when installed into a superconducting radio-frequency gun. The new configuration is obtained by a coating of Nb thin film grown on a disk of Pb via pulsed laser deposition. The central emitting area of Pb is masked by a shield to avoid the Nb deposition. The nanomechanical properties of the Nb film, obtained through nanoindentation measurements, reveal a hardness of 2.8±0.3 GPa, while the study of the electrical resistivity of the film shows the appearance of the superconducting transitions at 9.3 K and 7.3 K for Nb and Pb, respectively, very close to the bulk material values. Additionally, morphological, structural and contamination studies of Nb thin film expose a very low droplet density on the substrate surface, a small polycrystalline orientation of the films and a low contamination level. These results, together with the acceptable Pb quantum efficiency of 2×10-5 found at 266 nm, demonstrate the potentiality of the new concept photocathode.

  1. Large Area Deposition of MoS2 by Pulsed Laser Deposition with In-Situ Thickness Control

    KAUST Repository

    Serna, Martha I.

    2016-05-24

    A scalable and catalyst-free method to deposit stoichiometric Molybdenum Disulfide (MoS2) films over large areas is reported with the maximum area limited by the size of the substrate holder. The method allows deposition of MoS2 layers on a wide range of substrates without any additional surface preparation including single crystals (sapphire and quartz), polycrystalline (HfO2), and amorphous (SiO2). The films are deposited using carefully designed MoS2 targets fabricated with excess of sulfur (S) and variable MoS2 and S particle size. Uniform and layered MoS2 films as thin as two monolayers, with an electrical resistivity of 1.54 × 104 Ω cm-1 were achieved. The MoS2 stoichiometry was as confirmed by High Resolution Rutherford Backscattering Spectrometry (HRRBS). With the method reported here, in situ graded MoS2 films ranging from ~1 to 10 monolayers can also be deposited.

  2. Large-Area Deposition of MoS2 by Pulsed Laser Deposition with In Situ Thickness Control.

    Science.gov (United States)

    Serna, Martha I; Yoo, Seong H; Moreno, Salvador; Xi, Yang; Oviedo, Juan Pablo; Choi, Hyunjoo; Alshareef, Husam N; Kim, Moon J; Minary-Jolandan, Majid; Quevedo-Lopez, Manuel A

    2016-06-28

    A scalable and catalyst-free method to deposit stoichiometric molybdenum disulfide (MoS2) films over large areas is reported, with the maximum area limited by the size of the substrate holder. The method allows deposition of MoS2 layers on a wide range of substrates without any additional surface preparation, including single-crystal (sapphire and quartz), polycrystalline (HfO2), and amorphous (SiO2) substrates. The films are deposited using carefully designed MoS2 targets fabricated with excess sulfur and variable MoS2 and sulfur particle size. Uniform and layered MoS2 films as thin as two monolayers, with an electrical resistivity of 1.54 × 10(4) Ω cm(-1), were achieved. The MoS2 stoichiometry was confirmed by high-resolution Rutherford backscattering spectrometry. With the method reported here, in situ graded MoS2 films ranging from ∼1 to 10 monolayers can be deposited.

  3. Pulsed laser deposition of aluminum-doped ZnO films at 355 nm

    DEFF Research Database (Denmark)

    Holmelund, E.; Schou, Jørgen; Thestrup Nielsen, Birgitte;

    2004-01-01

    Conducting, transparent films of aluminium-doped ZnO (AZO) have been produced at the laser wavelength 355 nm. The most critical property, the electric resistivity, is up to a factor of 8 above that for films produced at shorter wavelengths. In contrast, the transmission of visible light through...

  4. In Situ Creation of Nanoparticles from YBCO by Pulsed Laser Deposition (Postprint)

    Science.gov (United States)

    2012-02-01

    nitrogen temperature maintaining current densities above 105 A/cm2 even at a few tesla [1]. Even so, improvements can still be made in its overall...nanoparticles of Si were generated by car - rying out the laser ablation of Si at fairly high pressures (on the order of several Torr) [30,31

  5. Production of high-performance and improved-durability Pt-catalyst /support for proton-exchange-membrane fuel cells with pulsed laser deposition

    Science.gov (United States)

    Huang, Ting-Wei; Qayyum, Hamza; Lin, Guan-Ren; Chen, Szu-yuan; Tseng, Chung-Jen

    2016-06-01

    Pulsed laser deposition in Ar atmosphere is used to deposit Pt nanoparticles onto gas diffusion layer, and its application to proton-exchange-membrane fuel cell is optimized and characterized. When used at anode side, with a Pt loading of 17 μg cm-2 the fuel-cell current density at 0.6 V reaches 1.08 A cm-2, which is close to that of a cell with the anode made by conventional slurry process using E-TEK Pt /C of 200 μg cm-2 Pt loading. The usage of Pt is decreased by 12 fold. Such a low usage of Pt prepared by pulsed laser deposition can be ascribed to the prevention of forming isolated regions that occurs with Pt /C slurry, good dispersion of Pt particles on support, and small particle sizes of 2-3 nm. Furthermore, using accelerated degradation test, it is found that the pulsed laser deposition sample retains 60% of its initial electrochemical surface area after 5000 potential cycles, much higher than that with E-TEK Pt /C, which retains only 7% of its initial electrochemical surface area. The higher electrochemical durability can be attributed to the higher degree of graphitization in the gas diffusion layer used as compared with the carbon black in E-TEK Pt /C, which leads to stronger binding of the Pt nanoparticles onto the carbon support and stronger corrosion resistance of the carbon support.

  6. Optimization of conditions for growth of vanadium dioxide thin films on silicon by pulsed-laser deposition

    Directory of Open Access Journals (Sweden)

    Keisuke Shibuya

    2015-10-01

    Full Text Available We systematically examined the effects of the substrate temperature (TS and the oxygen pressure (PO2 on the structural and optical properties polycrystalline V O2 films grown directly on Si(100 substrates by pulsed-laser deposition. A rutile-type V O2 phase was formed at a TS ≥ 450 °C at PO2 values ranging from 5 to 20 mTorr, whereas other structures of vanadium oxides were stabilized at lower temperatures or higher oxygen pressures. The surface roughness of the V O2 films significantly increased at growth temperatures of 550 °C or more due to agglomeration of V O2 on the surface of the silicon substrate. An apparent change in the refractive index across the metal–insulator transition (MIT temperature was observed in V O2 films grown at a TS of 450 °C or more. The difference in the refractive index at a wavelength of 1550 nm above and below the MIT temperature was influenced by both the TS and PO2, and was maximal for a V O2 film grown at 450 °C under 20 mTorr. Based on the results, we derived the PO2 versus 1/TS phase diagram for the films of vanadium oxides, which will provide a guide to optimizing the conditions for growth of V O2 films on silicon platforms.

  7. Optoelectronic Properties and Structural Characterization of GaN Thick Films on Different Substrates through Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    Wei-Kai Wang

    2017-01-01

    Full Text Available Approximately 4-μm-thick GaN epitaxial films were directly grown onto a GaN/sapphire template, sapphire, Si(111, and Si(100 substrates by high-temperature pulsed laser deposition (PLD. The influence of the substrate type on the crystalline quality, surface morphology, microstructure, and stress states was investigated by X-ray diffraction (XRD, photoluminescence (PL, atomic force microscopy (AFM, transmission electron microscopy (TEM, and Raman spectroscopy. Raman scattering spectral analysis showed a compressive film stress of −0.468 GPa for the GaN/sapphire template, whereas the GaN films on sapphire, Si(111, and Si(100 exhibited a tensile stress of 0.21, 0.177, and 0.081 GPa, respectively. Comparative analysis indicated the growth of very close to stress-free GaN on the Si(100 substrate due to the highly directional energetic precursor migration on the substrate’s surface and the release of stress in the nucleation of GaN films during growth by the high-temperature (1000 °C operation of PLD. Moreover, TEM images revealed that no significant GaN meltback (Ga–Si etching process was found in the GaN/Si sample surface. These results indicate that PLD has great potential for developing stress-free GaN templates on different substrates and using them for further application in optoelectronic devices.

  8. Control of the magnetic properties of LaMnO3 epitaxial thin films grown by Pulsed Laser Deposition

    Science.gov (United States)

    Martinez, Benjamin; Roqueta, Jaume; Pomar, Alberto; Balcells, Lluis; Frontera, Carlos; Konstantinovic, Zorica; Sandiumenge, Felip; Santiso, Jose; Advanced materials characterization Team; Thin films growth Team

    2015-03-01

    LaMnO3 (LMO), the parent compound of colossal magnetoresistance based manganites has gained renewed attention as a building block in heterostructures with unexpected properties. In its bulk phase, stoichiometric LMO is an A-type antiferromagnetic (AFM) insulator (TN = 140K) with orthorhombic structure that easily accommodate an oxygen excess by generating cationic (La or Mn) vacancies. As a result, a fraction of Mn 3+ changes to Mn 4+ leading to a double-exchange mediated ferromagnetic (FM) behavior. In thin films the AFM phase has been elusive up to now and thin films with FM ordering are usually reported. In this work, we have systematically studied the growth process of LaMnO3 thin films by pulsed laser deposition on SrTiO3 (001) substrates under different oxygen partial pressures (PO2) . A close correlation between the structure (explored by XRD) and the magnetic properties (SQUID measurements) of the films with PO2 has been identified. At high PO2 FM behavior is observed. In contrast, at very low PO2, the results obtained for unit cell volume (close to stoichiometric bulk values) and magnetic moment (0.2 μB/Mn) strongly indicate antiferromagnetic ordering. We acknowledge financial support from the Spanish MINECO (MAT2012-33207).

  9. Optical properties of pulsed laser deposited amorphous (GeSe2)100- x -Bi x films

    Science.gov (United States)

    Pan, R. K.; Tao, H. Z.; Zang, H. C.; Zhao, X. J.; Zhang, T. J.

    2010-06-01

    Amorphous (GeSe2)100- x -Bi x ( x=0, 0.4, 2 and 4) films were prepared by the pulsed laser deposition technique. The optical transmission spectra, absorption spectra and Raman spectra of the films were measured. The short-wavelength absorption edges in the strong absorption region of the films were described using the ‘non-direct-transition’ model proposed by Tauc and the optical band gaps (Eg^{opt}) were determined. The Urbach energy ( E u) was derived in the exponential part of the absorption edge. Both Eg^{opt} and Tauc slopes ( B 1/2) decreased with increasing Bi content, while E u had the opposite trend. The refractive indices of the films were calculated from the transmission spectra by using the Swanepoel method. Analysis of Raman spectra and absorption spectra shows that Bi addition decreases the mean bond energy and increases E u in the amorphous films, which caused the decrease of Eg^{opt}. The changes of the refractive indices are also discussed.

  10. Mössbauer and Magnetic Properties of Coherently Mixed Magnetite-Cobalt Ferrite Grown by Infrared Pulsed-Laser Deposition

    Directory of Open Access Journals (Sweden)

    Juan de la Figuera

    2015-12-01

    Full Text Available We have studied the magnetic properties and the composition of cobalt ferrite single crystal films on SrTiO3 : Nb grown by infrared pulsed-laser deposition. Mössbauer spectra have been recorded from both the target used to grow the films and the films themselves. The Mössbauer spectra of the target taken at low temperatures show a strong dependence of the recoil free fraction of the octahedral sites with temperature. The films composition, with a coexistence of Co-enriched cobalt ferrite and magnetite, has been estimated assuming a similar ratio of the recoil free fractions of the films. X-ray absorption and x-ray magnetic circular dichroism measurements confirm the valence composition of the film and show ferromagnetic Fe-Co coupling in the films with a coercive field around 0.5 T at room temperature. The combination of these characterization techniques allows establishing the coherent structural and magnetic properties of this biphase system.

  11. Ultrafast carrier dynamics of CdSe quantum dots prepared by pulse laser deposition for photovoltaic applications

    Science.gov (United States)

    Mahat, Meg; Yakami, Baichhabi; Qilin Dai, Qilin; Tang, Jinke; Pikal, Jon

    2013-03-01

    Quantum-dot sensitized solar cells are a promising alternative to existing photovoltaic technology. Over the last decade solution based colloidal quantum dots (QDs) have been extensively studied. Here we have carried out ultrafast transient absorption measurements on CdSe QDs fabricated using pulse laser deposition (PLD) in order to understand the carrier relaxation dynamics in these nanostructures. The differential transmission measurements show that the PLD QDs have a very fast decay process resulting in a recovery time of less than 10 picoseconds. This is in stark contrast to the colloidal QDs that show a decay process of more than 4 nanoseconds. We also find that the fast decay process observed in the PLD QDs is a function of the carriers density generated in CdSe QDs. To understand these carrier relaxation processes and improve the optical properties of the QDs we perform transient absorption measurements on PLD QDs prepared in different media (e.g. water, methanol, ethanol), under different growth conditions, and with and without ligand. We present a comparison study of the carrier relaxation dynamics in these PLD grown QDs to provide insight into the competing relaxation effects and guide their use in Quantum-dot sensitized solar cells. DOE

  12. Polarized Raman study on the lattice structure of BiFeO3 films prepared by pulsed laser deposition

    KAUST Repository

    Yang, Yang

    2014-11-01

    Polarized Raman spectroscopy was used to study the lattice structure of BiFeO3 films on different substrates prepared by pulsed laser deposition. Interestingly, the Raman spectra of BiFeO3 films exhibit distinct polarization dependences. The symmetries of the fundamental Raman modes in 50-700 cm-1 were identified based on group theory. The symmetries of the high order Raman modes in 900-1500 cm-1 of BiFeO3 are determined for the first time, which can provide strong clarifications to the symmetry of the fundamental peaks in 400-700 cm-1 in return. Moreover, the lattice structures of BiFeO3 films are identified consequently on the basis of Raman spectroscopy. BiFeO3 films on SrRuO3 coated SrTiO3 (0 0 1) substrate, CaRuO3 coated SrTiO3 (0 0 1) substrate and tin-doped indium oxide substrate are found to be in the rhombohedral structure, while BiFeO3 film on SrRuO3 coated Nb: SrTiO3 (0 0 1) substrate is in the monoclinic structure. Our results suggest that polarized Raman spectroscopy would be a feasible tool to study the lattice structure of BiFeO3 films.

  13. Dielectric, impedance and ferroelectric characteristics of c-oriented bismuth vanadate films grown by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, Neelam [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India); Krupanidhi, S.B. [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India); Varma, K.B.R. [Materials Research Centre, Indian Institute of Science, Bangalore 560012 (India)]. E-mail: kbrvarma@mrc.iisc.ernet.in

    2007-03-15

    Ferroelectric bismuth vandante, Bi{sub 2}VO{sub 5.5} (BVO) thin films with layered perovskite structure were deposited by pulsed excimer laser ablation technique on (1 1 1) Pt/TiO{sub 2}/SiO{sub 2}/Si substrates. The polarization hysteresis (P versus E) studies on the BVO thin films at 300 K confirmed the remnant polarization (P {sub r}) and coercive field (E {sub c}) to be 5.6 {mu}C/cm{sup 2} and 113 kV/cm, respectively. The same was corroborated via the capacitance-voltage measurements. The dielectric response and conduction mechanism of BVO thin films under small ac fields were analyzed using impendence spectroscopy. A strong low frequency dielectric dispersion (LFDD) was found to exist in these films, which was ascribed to the presence of the ionized space charge carriers such as oxygen ion vacancies and interfacial polarization. The room temperature dielectric constant and the loss (D) at 100 kHz were 233 and 0.07, respectively. The thermal activation energy for the relaxation process of the ionized space charge carriers was 0.85 eV. The frequency characteristics of BVO thin films under study showed universal dynamic response that was proposed by Jonscher for the systems associated with quasi-free charges.

  14. 3-D matrix template-assisted growth of oriented oxide nanowire arrays using glancing angle pulsed laser deposition

    Science.gov (United States)

    Wright, N.; Mateo-Feliciano, D.; Ostoski, A.; Mukherjee, P.; Witanachchi, S.

    Nanosphere lithography is a combination of different methods to nanofabrication. In this work nanosphere lithography is used to study the growth of Zinc Oxide Nano-columns (ZnO NCs) on different diameter Silica Nanosphere (SNS) self-assembled templates. ZnO NCs are promising building blocks for many existing and emerging optical, electrical, and piezoelectric devices, specifically, the seeded growth of other oxide materials. Recently, reports have shown a ferroelectric phase of zinc stannate (ZnSnO3) and while lead zirconium titanate oxide (PZT) has been the main material of interest in ferroelectric and piezoelectric applications, the toxicity of lead has been of great concern. The possibility of developing lead free piezoelectric materials is of great interest in the ferroelectric community. Langmuir-Blodgett method was used to construct a self-assembled monolayer of SNSs on silicon substrates. Oriented ZnO NCs were grown on top of the spheres using the glancing angle pulsed laser deposition technique. Columns were formed in a spatially ordered closed-packed hexagonal configuration. Growth of ZnO NCs was studied as function of ambient Oxygen pressure with SNS size ranging from 250-1000 nm. Cross-sectional Scanning Electron Microscopy and X-ray diffraction (XRD) were used to study the template structure. Relative aspect ratios were studied and showed tunability of column dimensions with sphere size. XRD revealed ZnO NC arrays were c-axis oriented with hexagonal wurtzite structure.

  15. Thin yttrium iron garnet films grown by pulsed laser deposition: Crystal structure, static, and dynamic magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, N. S., E-mail: nsokolov@fl.ioffe.ru; Fedorov, V. V.; Korovin, A. M.; Suturin, S. M.; Baranov, D. A.; Gastev, S. V.; Krichevtsov, B. B.; Bursian, V. E.; Lutsev, L. V. [Ioffe Physical-Technical Institute of Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Maksimova, K. Yu.; Grunin, A. I. [Immanuel Kant Baltic Federal University, Kaliningrad 236041 (Russian Federation); Tabuchi, M. [Synchrotron Radiation Research Center, Nagoya University, Nagoya 464-8603 (Japan)

    2016-01-14

    Pulsed laser deposition has been used to grow thin (10–84 nm) epitaxial layers of Yttrium Iron Garnet Y{sub 3}Fe{sub 5}O{sub 12} (YIG) on (111)–oriented Gadolinium Gallium Garnet substrates at different growth conditions. Atomic force microscopy showed flat surface morphology both on micrometer and nanometer scales. X-ray diffraction measurements revealed that the films are coherent with the substrate in the interface plane. The interplane distance in the [111] direction was found to be by 1.2% larger than expected for YIG stoichiometric pseudomorphic film indicating presence of rhombohedral distortion in this direction. Polar Kerr effect and ferromagnetic resonance measurements showed existence of additional magnetic anisotropy, which adds to the demagnetizing field to keep magnetization vector in the film plane. The origin of the magnetic anisotropy is related to the strain in YIG films observed by XRD. Magneto-optical Kerr effect measurements revealed important role of magnetization rotation during magnetization reversal. An unusual fine structure of microwave magnetic resonance spectra has been observed in the film grown at reduced (0.5 mTorr) oxygen pressure. Surface spin wave propagation has been demonstrated in the in-plane magnetized films.

  16. Synthesis and modification of mesoporous silica and the preparation of molecular sieve thin films via pulsed laser deposition

    Science.gov (United States)

    Coutinho, Decio Heringer

    2001-07-01

    Hexagonal mesoporous DAM-1 (Dallas Amorphous Material-1) was prepared using Vitamin E TPGS as the structure-directing agent. Depending upon the temperature and gel composition, highly ordered and hydrothermally stable DAM-1 with various morphologies could be achieved including spheres, gyroids, discoid, hexagonal plates and rods. This synthesis was modified to prepare hybrid organic-inorganic amine and thiol bifunctionalized DAM-1 by direct co-condensation under acidic conditions. Patterned DAM-1 thin films were prepared on patterned transparencies utilizing pulsed laser deposition (PLD) and line patterning techniques. DAM-1 laser ablation onto the patterned substrate followed by hydrothermal treatment resulted in a densely packed film. Removal of the patterned lines by sonication revealed patterned DAM-1 films. Thin films of zeolite type X were also prepared using the PLD technique. Laser ablation of zeolite X onto TiN-coated silicon wafers followed by a hydrothermal treatment resulted in partially oriented, crystalline membranes. Hydrothermal treatment of PLD films on stainless steel mesh produced a coated wire mesh with a 3-mum thick zeolite X film. A novel strategy for imprinting mesoporous SBA-15 that combines a triblock copolymer template and a chiral ruthenium complex is reported. A chiral PEO helix was formed by the chiral ruthenium complex interaction with the block copolymer during the synthesis of SBA-15. Upon removal of the chiral ruthenium complex, a stereospecfic cavity was created. Preliminary results indicated stereoselective absorption of Delta or Λ-Ru(phen)3 2+ isomer from a racemic mixture could be achieved depending on the chirality of the PEO chain. Practicum Two. The industrial practicum report describes the process development unit (PDU) 3-pentenenitrile (3PN) refining operation. This distillation works was operated to refine crude 3PN product, which contained 3PN, 2-methyl-3-butenenitrile (2M3BN), and other byproducts. This report also

  17. Structural and optical properties of phenylalanine and tyrosine thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Perez, M A [Laboratoire de Physico-Chimie des Materiaux Luminescents, CNRS-Universite Lyon I, 10 rue Andre-Marie Ampere, 69622 Villeurbanne (France); Garapon, C [Laboratoire de Physico-Chimie des Materiaux Luminescents, CNRS-Universite Lyon I, 10 rue Andre-Marie Ampere, 69622 Villeurbanne (France); Champeaux, C [Science des Procedes Ceramiques et Traitement de Surface, CNRS-Universite de Limoges, 123, avenue Albert Thomas, 87060 Limoges (France); Orlianges, J C [Science des Procedes Ceramiques et Traitement de Surface, CNRS-Universite de Limoges, 123, avenue Albert Thomas, 87060 Limoges (France)

    2007-04-15

    Thin films of the amino-acids phenylalanine (Phe) and tyrosine (Tyr) were prepared by PLD with a KrF laser at fluences of some hundreds mJ/cm{sup 2}. Conservation of the chemical structure and a metastable modification of the molecular interactions are evidenced by IR spectroscopy. The evolution of the refractive indices with fluence was correlated with the structure determined by X ray diffraction. The plume expansion imaging was achieved.

  18. Structural and optical properties of phenylalanine and tyrosine thin films prepared by pulsed laser deposition

    Science.gov (United States)

    Hernandez-Perez, M. A.; Garapon, C.; Champeaux, C.; Orlianges, J. C.

    2007-04-01

    Thin films of the amino-acids phenylalanine (Phe) and tyrosine (Tyr) were prepared by PLD with a KrF laser at fluences of some hundreds mJ/cm2. Conservation of the chemical structure and a metastable modification of the molecular interactions are evidenced by IR spectroscopy. The evolution of the refractive indices with fluence was correlated with the structure determined by X ray diffraction. Phe plume expansion imaging was achieved.

  19. Effect of Hydrogen ion beam irradiation onto the FIR reflectivity of pulsed laser deposited mirror like Tungsten films

    Energy Technology Data Exchange (ETDEWEB)

    Mostako, A.T.T. [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781 039 (India); Khare, Alika, E-mail: alika@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781 039 (India); Rao, C.V.S.; Raole, Prakash M.; Vala, Sudhirsinh; Jakhar, Shrichand; Basu, T.K.; Abhangi, Mitul; Makwana, Rajinikant J. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

    2012-04-15

    Graphical abstract: The specular FIR reflectivity of the W{sub 1}, W{sub 2}, W{sub 3} and W{sub 4} mirrors before and after 8 keV Hydrogen ion beam irradiation. Highlights: Black-Right-Pointing-Pointer Mirror like W thin films were obtained via PLD. Black-Right-Pointing-Pointer The maximum thickness of the Tungsten thin film was {approx}324 nm. Black-Right-Pointing-Pointer Effect of H-ion beam irradiation on the quality of PLD W mirror is reported. Black-Right-Pointing-Pointer Post exposure reflectivity of Tungsten thin films was hardly changed by 2%. - Abstract: The optical quality of the First Mirrors (FMs) of a fusion device (burning plasma experiments, ITER) deteriorates due to the erosion by charge exchange neutrals, re-deposition of the eroded material and the lattice damage by the bombardment of the high energetic particles. This degradation of the optical quality of the plasma facing components in such a harsh environment is a serious concern for the reliability of the spectroscopic based optical diagnostics using FM of a fusion device. In this paper, the effect of 8 keV Hydrogen ion beam irradiation onto the FIR reflectivity of Tungsten thin film mirror is presented. The Tungsten thin films were prepared via Pulsed Laser Deposition (PLD) technique. The Tungsten mirrors were subjected to X-ray Diffraction (XRD), Energy Dispersive X-ray (EDX), Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) for characterization. The specular reflectivities of the Tungsten mirrors before and after exposure to ion beam were recorded with Fourier Transform of Infra-Red (FTIR) technique. The ion penetration depth and straggle into Tungsten thin film and stainless steel (SS) substrate were estimated by Transport of Ions in Matter (TIRM) simulation code. The changes in post exposure IR reflectivity were interpreted in terms of these parameters.

  20. Reconstructing the energy band electronic structure of pulsed laser deposited CZTS thin films intended for solar cell absorber applications

    Science.gov (United States)

    Pandiyan, Rajesh; Oulad Elhmaidi, Zakaria; Sekkat, Zouheir; Abd-lefdil, Mohammed; El Khakani, My Ali

    2017-02-01

    We report here on the use of pulsed KrF-laser deposition (PLD) technique for the growth of high-quality Cu2ZnSnS4 (CZTS) thin films onto Si, and glass substrates without resorting to any post sulfurization process. The PLD-CZTS films were deposited at room temperature (RT) and then subjected to post annealing at different temperatures ranging from 200 to 500 °C in Argon atmosphere. The X-ray diffraction and Raman spectroscopy confirmed that the PLD films crystallize in the characteristic kesterite CZTS structure regardless of their annealing temperature (Ta), but their crystallinity is much improved for Ta ≥ 400 °C. The PLD-CZTS films were found to exhibit a relatively dense morphology with a surface roughness (RMS) that increases with Ta (from ∼14 nm at RT to 70 nm at Ta = 500 °C with a value around 40 nm for Ta = 300-400 °C). The optical bandgap of the PLD-CZTS films, was derived from UV-vis transmission spectra analysis, and found to decrease from 1.73 eV for non-annealed films to ∼1.58 eV for those annealed at Ta = 300 °C. These band gap values are very close to the optimum value needed for an ideal solar cell absorber. In order to achieve a complete reconstruction of the one-dimensional energy band structure of these PLD-CZTS absorbers, we have combined both XPS and UPS spectroscopies to determine their chemical bondings, the position of their valence band maximum (relative to Fermi level), and their work function values. This enabled us to sketch out, as accurately as possible, the band alignment of the heterojunction interface formed between CZTS and both CdS and ZnS buffer layer materials.

  1. Dense zig-zag microstructures in YSZ thin films by pulsed laser deposition

    Directory of Open Access Journals (Sweden)

    Dieter Stender

    2015-01-01

    Full Text Available The very brittle oxygen ion conductor yttria stabilized zirconia (YSZ is a typical solid electrolyte for miniaturized thin film fuel cells. In order to decrease the fuel cell operating temperature, the thickness of yttria stabilized zirconia thin films is reduced. Often, these thin membranes suffer from mechanical failure and gas permeability. To improve these mechanical issues, a glancing angle deposition approach is used to grow yttria stabilized zirconia thin films with tilted columnar structures. Changes of the material flux direction during the deposition result in a dense, zigzag-like structure with columnar crystallites. This structure reduces the elastic modulus of these membranes as compared to columnar yttria stabilized zirconia thin films as monitored by nano-indentation which makes them more adaptable to applied stress.

  2. Instrumentation to Support the Research Program of Pulsed Laser Deposition of Polymer Nanocomposite Films

    Science.gov (United States)

    2015-05-19

    nanocomposites of PMMA and carbon nanotubes (CNTs) with MAPLE. MAPLE targets were prepared by first dissolving PMMA in toluene at a concentration... emission . This is due to much better control of the deposition process of the materials of different nature. In order to extend greatly the...mathematics, engineering or technology fields : Student Metrics This section only applies to graduating undergraduates supported by this agreement in this

  3. Titanium dioxide thin films deposited by pulsed laser deposition and integration in radio frequency devices: Study of structure, optical and dielectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Orlianges, Jean-Christophe, E-mail: jean-christophe.orlianges@unilim.fr [SPCTS, UMR 7315, Universite de Limoges/CNRS, 12 rue Atlantis, 87068 Limoges Cedex (France); Crunteanu, Aurelian; Pothier, Arnaud [XLIM, UMR 7252, Universite de Limoges/CNRS, 123, avenue Albert Thomas, 87060 Limoges Cedex (France); Merle-Mejean, Therese [SPCTS, UMR 7315, Universite de Limoges/CNRS, 12 rue Atlantis, 87068 Limoges Cedex (France); Blondy, Pierre [XLIM, UMR 7252, Universite de Limoges/CNRS, 123, avenue Albert Thomas, 87060 Limoges Cedex (France); Champeaux, Corinne [SPCTS, UMR 7315, Universite de Limoges/CNRS, 12 rue Atlantis, 87068 Limoges Cedex (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer We have grown TiO{sub 2} thin films by PLD on c-sapphire substrate with pre-patterned out-plane capacitor structures. Black-Right-Pointing-Pointer Raman and XRD analyses indicate an evolution from 'amorphous' to anatase and rutile phase. Black-Right-Pointing-Pointer Thin films optical properties are investigated using spectroscopic ellipsometry and transmission measurements. Black-Right-Pointing-Pointer Permittivity measurements reveal high dielectric constant {epsilon}{sub r} = 120 of 600 Degree-Sign C-grown TiO{sub 2} thin films. - Abstract: Titanium dioxide presents a wide range of technological application possibilities due to its dielectric, electrochemical, photocatalytic and optical properties. The three TiO{sub 2} allotropic forms: anatase, rutile and brookite are also interesting, since they exhibit different properties, stabilities and growth modes. For instance, rutile has a high dielectric permittivity, of particular interest for the integration as dielectric in components such as microelectromechanical systems (MEMS) for radio frequency (RF) devices. In this study, titanium dioxide thin films are deposited by pulsed laser deposition. Characterizations by Raman spectroscopy and X-ray diffraction show the evolution of the structural properties. Thin films optical properties are investigated using spectroscopic ellipsometry and transmission measurements from UV to IR range. Co-planar waveguide (CPW) devices are fabricated based on these films. Their performances are measured in the RF domain and compared to simulation, leading to relative permittivity values in the range 30-120, showing the potentialities of the deposited material for capacitive switches applications.

  4. Nanofabrication with pulsed lasers.

    Science.gov (United States)

    Kabashin, Av; Delaporte, Ph; Pereira, A; Grojo, D; Torres, R; Sarnet, Th; Sentis, M

    2010-02-24

    An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser-matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.

  5. Characterization of pulsed laser deposition grown V2O3 converted VO2

    Science.gov (United States)

    Majid, Suhail; Shukla, D. K.; Rahman, F.; Gautam, Kamini; Sathe, V. G.; Choudhary, R. J.; Phase, D. M.

    2016-10-01

    Controllable tuning of Metal-insulator transition in VxOy thin film has been a field of extensive research. However controlled synthesis of desired Vanadium oxide phase is a challenging task. We have successfully achieved VO2 phase on Silicon substrate after post deposition annealing treatment to the PLD grown as deposited V2O3 thin films. The annealed thin film was characterized by x-ray diffraction (XRD), resistivity, Raman spectroscopy, X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) measurements. XRD confirms the crystalline nature and growth of VO2 phase in thin film. The characteristic MIT was observed from resistivity measurements and transition temperature appeared at lower value around 336 K, compared to bulk VO2. The structural transition accompanied with MIT from lower temperature monoclinic phase to higher temperature Rutile phase became evident from temperature dependent Raman measurements. Chemical state of vanadium was examined using XAS and XPS measurements which confirm the presence of +4 oxidation state of vanadium in thin film.

  6. Effect of Ta on the microstructure and hardness of Stellite 6 coating deposited by low power pulse laser treatments

    NARCIS (Netherlands)

    Farnia, A.; Ghaini, F. Malek; Rao, J. C.; Ocelik, V.; De Hosson, J. Th M.

    2012-01-01

    Stellite 6 hardfacing alloy with different Ta contents is successfully synthesized with an in situ process on low carbon ferritic steel substrate by Nd:YAG pulsed laser cladding with pre-placed Stellite 6 and Ta mixed powders. The effect of different amounts of Ta on the microstructure of the Stelli

  7. Effect of Ta on the microstructure and hardness of Stellite 6 coating deposited by low power pulse laser treatments

    NARCIS (Netherlands)

    Farnia, A.; Ghaini, F. Malek; Rao, J. C.; Ocelik, V.; De Hosson, J. Th M.

    2012-01-01

    Stellite 6 hardfacing alloy with different Ta contents is successfully synthesized with an in situ process on low carbon ferritic steel substrate by Nd:YAG pulsed laser cladding with pre-placed Stellite 6 and Ta mixed powders. The effect of different amounts of Ta on the microstructure of the

  8. Pulsed inductive HF laser

    Energy Technology Data Exchange (ETDEWEB)

    Razhev, A M; Kargapol' tsev, E S [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Churkin, D S; Demchuk, S V [Novosibirsk State University, Novosibirsk (Russian Federation)

    2016-03-31

    We report the results of experimentally investigated dependences of temporal, spectral and spatial characteristics of an inductive HF-laser generation on the pump conditions. Gas mixtures H{sub 2} – F{sub 2}(NF{sub 3} or SF6{sub 6}) and He(Ne) – H{sub 2} – F{sub 2}(NF{sub 3} or SF{sub 6}) were used as active media. The FWHM pulse duration reached 0.42 μs. This value corresponded to a pulsed power of 45 kW. For the first time, the emission spectrum of an inductive HF laser was investigated, which consisted of seven groups of bands with centres around the wavelengths of 2732, 2736, 2739, 2835, 2837, 2893 and 2913 nm. The cross section profile of the laser beam was a ring with a diameter of about 20 mm and width of about 5 mm. Parameters of laser operation in the repetitively pulsed regime were sufficiently stable. The amplitude instability of light pulses was no greater than 5% – 6%. (lasers)

  9. Nanofabrication with Pulsed Lasers

    Directory of Open Access Journals (Sweden)

    Kabashin AV

    2010-01-01

    Full Text Available Abstract An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3, is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser–matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.

  10. Surface photovoltage spectroscopy of pulsed laser deposited undoped ZnSe/n+GaAs

    Science.gov (United States)

    Ganguli, Tapas; Kumar, Shailendra; Kukreja, L. M.; Rustagi, K. C.

    2002-03-01

    We report surface photovoltage (SPV) spectra of ZnSe thin films deposited on n+GaAs substrates in the wavelength range of 400-800 nm. In the above bandgap region of ZnSe (below 450 nm), we find that the major contribution to SPV comes from trapping and re-emission from the slow states at the ZnSe surface and ZnSe/GaAs interface. The effect of interference of light on the SPV spectra, has been analysed for subbandgap wavelength excitation of ZnSe (470-800 nm). In spite of the presence of a large number of subbandgap states in ZnSe, the major contribution to SPV in this wavelength range comes from the substrate. The difference in the magnitudes of the SPV between the bare n+GaAs and the ZnSe/n+GaAs is due to the reduction of surface recombination velocity (SRV) of the minority carriers in n+GaAs.

  11. Surface photovoltage spectroscopy of pulsed laser deposited undoped ZnSe/n{sup +}GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Ganguli, Tapas; Kumar, Shailendra; Kukreja, L.M.; Rustagi, K.C. [Laser Physics Division, Centre for Advanced Technology, Indore (India)

    2002-03-04

    We report surface photovoltage (SPV) spectra of ZnSe thin films deposited on n{sup +}GaAs substrates in the wavelength range of 400-800 nm. In the above bandgap region of ZnSe (below 450 nm), we find that the major contribution to SPV comes from trapping and re-emission from the slow states at the ZnSe surface and ZnSe/GaAs interface. The effect of interference of light on the SPV spectra, has been analysed for subbandgap wavelength excitation of ZnSe (470-800 nm). In spite of the presence of a large number of subbandgap states in ZnSe, the major contribution to SPV in this wavelength range comes from the substrate. The difference in the magnitudes of the SPV between the bare n{sup +}GaAs and the ZnSe/n+GaAs is due to the reduction of surface recombination velocity (SRV) of the minority carriers in n{sup +}GaAs. (author)

  12. Structural, optical and electrical properties of AlSb thin films deposited by pulsed laser deposition using aluminum-antimony alloying target

    Science.gov (United States)

    Yang, Ke; Li, Bing; Zhang, Jingquan; Li, Wei; Wu, Lili; Zeng, Guanggen; Wang, Wenwu; Liu, Cai; Feng, Lianghuan

    2017-02-01

    AlSb films which are a promising absorber layer for thin film solar cells were grown on glass substrate at different substrate temperature ranging from room temperature to 400 °C on glass substrates using aluminum-antimony alloying target by pulsed laser deposition (PLD) technique. Structural, optical and electrical properties of AlSb thin films were studied by X-ray diffraction (XRD), ultraviolet-visible spectrophotometer and a home-made four-probe-contact high temperature system respectively. XRD pattern shows that AlSb film is amorphous at room temperature, but when substrate temperature is higher than 100 °C, AlSb films present cubic phase structure with the preferential orientation of (111) plane. And intensity of diffraction peaks of AlSb film prepared at substrate temperature of 200 °C are stronger than that of other substrate temperature. The electrical measurement results show that conductivity activation energy of AlSb film is 0.25 eV and 0.28 eV. The indirect optical band gap is about 1.63 eV, which is very close to its theoretical value of 1.62 eV. The results of energy dispersive spectrometer (EDS) indicated the ratio of Al to Sb of AlSb films is about 1:1.

  13. Pulsed laser deposition-assisted synthesis of porous WP2 nanosheet arrays integrated on graphite paper as a 3D flexible cathode for efficient hydrogen evolution

    Science.gov (United States)

    Pi, Mingyu; Guo, Weimeng; Wu, Tianli; Wang, Xiaodeng; Zhang, Dingke; Wang, Shuxia; Chen, Shijian

    2017-10-01

    Herein, porous WP2 nanosheet arrays integrated on graphite paper (P-WP2 NSs/GP) as 3D flexible cathode for electrocatalytic hydrogen evolution reaction (HER) are prepared by in situ phosphidation via vacuum encapsulation assisted by pulsed laser deposition technique. Compared to the electrode without pre-deposition process, the enhanced catalytic activities are attributed to the increased effective catalyst loading and the reinforced charge transport kinetics. The results make the present P-WP2 NSs/GP as a promising cathode for energy conversion and paves a new way for designing and fabricating efficient electrodes toward HER.

  14. Enhancing the light absorbance of polymer solar cells by introducing pulsed laser-deposited CuIn0.8Ga0.2Se2 nanoparticles

    OpenAIRE

    Zhao, Yu; LI, Hui; Liu, Xu-Jun; Guan, Lei-Lei; Li, Yan-Li; Sun, Jian; Ying, Zhi-Feng; Wu, Jia-Da; Xu,Ning

    2014-01-01

    Evenly separated crystalline CuIn0.8Ga0.2Se2 (CIGS) nanoparticles are deposited on ITO-glass substrate by pulsed laser deposition. Such CIGS layers are introduced between conjugated polymer layers and ITO-glass substrates for enhancing light absorbance of polymer solar cells. The P3HT:PCBM absorbance between 300 and 650 nm is enhanced obviously due to the introduction of CIGS nanoparticles. The current density-voltage curves of a P3HT:PCBM/CIGS solar cell demonstrate that the short-circuit cu...

  15. Pulsed laser-deposited nanocrystalline GdB6 thin films on W and Re as field emitters

    Science.gov (United States)

    Suryawanshi, Sachin R.; Singh, Anil K.; Phase, Deodatta M.; Late, Dattatray J.; Sinha, Sucharita; More, Mahendra A.

    2016-10-01

    Gadolinium hexaboride (GdB6) nanocrystalline thin films were grown on tungsten (W), rhenium (Re) tips and foil substrates using optimized pulsed laser deposition (PLD) technique. The X-ray diffraction analysis reveals formation of pure, crystalline cubic phase of GdB6 on W and Re substrates, under the prevailing PLD conditions. The field emission (FE) studies of GdB6/W and GdB6/Re emitters were performed in a planar diode configuration at the base pressure ~10-8 mbar. The GdB6/W and GdB6/Re tip emitters deliver high emission current densities of ~1.4 and 0.811 mA/cm2 at an applied field of ~6.0 and 7.0 V/µm, respectively. The Fowler-Nordheim ( F- N) plots were found to be nearly linear showing metallic nature of the emitters. The noticeably high values of field enhancement factor ( β) estimated using the slopes of the F- N plots indicate that the PLD GdB6 coating on W and Re substrates comprises of high-aspect-ratio nanostructures. Interestingly, the GdB6/W and GdB6/Re planar emitters exhibit excellent current stability at the preset values over a long-term operation, as compared to the tip emitters. Furthermore, the values of workfunction of the GdB6/W and GdB6/Re emitters, experimentally measured using ultraviolet photoelectron spectroscopy, are found to be same, ~1.6 ± 0.1 eV. Despite possessing same workfunction value, the FE characteristics of the GdB6/W emitter are markedly different from that of GdB6/Re emitter, which can be attributed to the growth of GdB6 films on W and Re substrates.

  16. Structural, morphological and optical characterizations of ZnO:Al thin films grown on silicon substrates by pulsed laser deposition

    Science.gov (United States)

    Alyamani, A.; Sayari, A.; Albadri, A.; Albrithen, H.; El Mir, L.

    2016-09-01

    The pulsed laser deposition (PLD) technique is used to grow Al-doped ZnO (AZO) thin films at 500 ° C on silicon substrates under vacuum or oxygen gas background from ablating AZO nanoparticle targets synthesized via the sol-gel process. The structural, morphological and optical properties were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and spectroscopic ellipsometry (SE) techniques. XRD and TEM images show that AZO powder has a wurtzite-type structure and is composed of small prismatic-like shape nanoparticles with an average size of 30nm. The structural properties of the AZO films grown under oxygen show no significant changes compared to those of the film grown under vacuum. However, the optical properties show a dependence on the growth conditions of the AZO films. Highly c -axis-oriented AZO thin films were obtained with grain size ˜ 15 nm. The stress in the AZO films is tensile as measured from the c -parameter. The dielectric function, the refractive index and the extinction coefficient as a function of the photon energy for the AZO films were determined by using spectroscopic ellipsometry measurements in the photon energy region from 1 to 6eV. The band gap energy was observed to slightly decrease in the presence of the O2 gas background and this may be attributed to the stress. The surface and volume energy loss functions are calculated and exhibit different behaviors in the energy range 1-6eV. Refractive indices of 1.9-2.1 in the visible region were obtained for the AZO films. Also, the electronic carrier concentration appears to be related to the presence of O2 during the growth process.

  17. Stimulation of osteogenic and angiogenic ability of cells on polymers by pulsed laser deposition of uniform akermanite-glass nanolayer.

    Science.gov (United States)

    Wu, Chengtie; Zhai, Dong; Ma, Hongshi; Li, Xiaomin; Zhang, Yali; Zhou, Yinghong; Luo, Yongxiang; Wang, Yueyue; Xiao, Yin; Chang, Jiang

    2014-07-01

    Polymer biomaterials have been widely used for bone replacement/regeneration because of their unique mechanical properties and workability. Their inherent low bioactivity makes them lack osseointegration with host bone tissue. For this reason, bioactive inorganic particles have been always incorporated into the matrix of polymers to improve their bioactivity. However, mixing inorganic particles with polymers always results in inhomogeneity of particle distribution in polymer matrix with limited bioactivity. This study sets out to apply the pulsed laser deposition (PLD) technique to prepare uniform akermanite (Ca2MgSi2O7, AKT) glass nanocoatings on the surface of two polymers (non-degradable polysulfone (PSU) and degradable polylactic acid (PDLLA)) in order to improve their surface osteogenic and angiogenic activity. The results show that a uniform nanolayer composed of amorphous AKT particles (∼30 nm) of thickness 130 nm forms on the surface of both PSU and PDLLA films with the PLD technique. The prepared AKT-PSU and AKT-PDLLA films significantly improved the surface roughness, hydrophilicity, hardness and apatite mineralization, compared with pure PSU and PDLLA, respectively. The prepared AKT nanocoatings distinctively enhance the alkaline phosphate (ALP) activity and bone-related gene expression (ALP, OCN, OPN and Col I) of bone-forming cells on both PSU and PDLLA films. Furthermore, AKT nanocoatings on two polymers improve the attachment, proliferation, VEGF secretion and expression of proangiogenic factors and their receptors of human umbilical vein endothelial cells (HUVEC). The results suggest that PLD-prepared bioceramic nanocoatings are very useful for enhancing the physicochemical, osteogenic and angiogenic properties of both degradable and non-degradable polymers for application in bone replacement/regeneration.

  18. ZnO homoepitaxy on the O polar face of hydrothermal and melt-grown substrates by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, D.J. [Nanovation SARL, Orsay (France); Technical Univ. of Troyes (France); CNRS, Troyes (France); Hosseini Teherani, F. [Nanovation SARL, Orsay (France); Largeteau, A.; Demazeau, G. [ICMCB-CNRS, Bordeaux 1 University (Science and Technology), Pessac (France); Moisson, C.; Turover, D. [Novasic, Savoie Technolac, Arche Bat. 4, BP 267, Le Bourget du Lac (France); Nause, J. [Cermet Inc., Atlanta, GA (United States); Garry, G. [Thales Research, Domaine de Corbeville, Orsay (France); Kling, R.; Gruber, T. [Ulm University, Department of Semiconductor Physics, Ulm (Germany); Waag, A. [Braunschweig Technical University, Institute of Semiconductor Technology, Braunschweig (Germany); Jomard, F.; Galtier, P.; Lusson, A. [LPSC-CNRS, Meudon (France); Monteiro, T.; Soares, M.J.; Neves, A.; Carmo, M.C.; Peres, M. [University of Aveiro, Physics Department, Aveiro (Portugal); Lerondel, G.; Hubert, C. [Technical University of Troyes-CNRS (FRE2671), 12 rue Marie Curie, BP 2060, Troyes (France)

    2007-07-15

    2 cm diameter hydrothermal ZnO crystals were grown and then made into substrates using both mechanical and chemical-mechanical polishing (CMP). CMP polishing showed superior results with an (0002) {omega} scan full width half maximum (FWHM) of 67 arcsec and an root mean square (RMS) roughness of 2 Aa. In comparison, commercial melt-grown substrates exhibited broader X-ray diffraction (XRD) linewidths with evidence of sub-surface crystal damage due to polishing, including a downward shift of c-lattice parameter. Secondary ion mass spectroscopy revealed strong Li, Fe, Co, Al and Si contamination in the hydrothermal crystals as opposed to the melt-grown substrates, for which glow discharge mass spectroscopy studies had reported high levels of Pb, Fe, Cd and Si. Low temperature photoluminescence (PL) studies indicated that the hydrothermal crystal had high defect and/or impurity concentrations compared with the melt-grown substrate. The dominant bound exciton for the melt-grown substrate was indexed to Al. ZnO films were grown using pulsed laser deposition. The melt-grown substrates gave superior results with XRD (0002) {omega} and 2{theta}/{omega} WHM of 124 and 34 arcsec, respectively. Atomic force microscope measurements indicated a low RMS roughness (1.9 nm) as confirmed by fringes in the XRD 2{theta}/{omega} scan. It was suggested that the improvement in XRD response relative to the substrate might be due to ''healing'' of sub-surface polishing damage due to the elevated T{sub s} used for the growth. Indeed the c-lattice parameter for the homoepitaxial layer on the melt-grown substrate had become that which would be expected for strain-free ZnO. Furthermore, the stability of the PL peak positions relative to bulk ZnO, confirmed that the films appear practically strain free. (orig.)

  19. Effect of residual stress on the microstructure of GaN epitaxial films grown by pulsed laser deposition

    Science.gov (United States)

    Wang, Haiyan; Wang, Wenliang; Yang, Weijia; Zhu, Yunnong; Lin, Zhiting; Li, Guoqiang

    2016-04-01

    The stress-free GaN epitaxial films have been directly grown by pulsed laser deposition (PLD) at 850 °C, and the effect of different stress on the microstructure of as-grown GaN epitaxial films has been explored in detail. The as-grown stress-free GaN epitaxial films exhibit very smooth surface without any particles and grains, which is confirmed by the smallest surface root-mean-square roughness of 2.3 nm measured by atomic force microscopy. In addition, they also have relatively high crystalline quality, which is proved by the small full-width at half maximum values of GaN(0002) and GaN (10 1 bar 2) X-ray rocking curves as 0.27° and 0.68°, respectively. However, when the growth temperature is lower or higher than 850 °C, internal or thermal stress would be increased in as-grown GaN epitaxial films. To release the larger stress, a great number of dislocations